Opinions on Traps powers?

Web Grenade: Yawn. Mostly I use it for the -fly, or to reduce recharge on AV's.
Caltrops: Put recharge in it. Use it to block chokepoints or to stand on and keep melees away.
Triage Beacon: Lots of people will tell you how useless this power is. Don't believe them. It doesn't LOOK like it's doing much, but the difference in your team's survivability is typically rather dramatic.
Acid Mortar: This is your bread and butter. Recharge until you hit ED, some accuracy, then either procs or defense debuff. You'll want to use this at every fight.
Force Field Generator: Important. Slot for defense. Not much point putting anything else in it, in my opinion.
Poison Trap: I find this to be a good hold. I don't as often use it as a trap. You'll need it for AV's and G_M's anyways.
Seeker Drones: VERY IMPORTANT. These are your tanks. I have mine slotted 3 recharge and 2 range right now. I use them to eat alpha strikes while weakening the mobs. They're great for that. Pop them into the middle of a group and everything will turn on them and attack. Then they look up and you've got some mayhem set up for them, and their big attacks are recharging.
Trip Mine: I actually end up using this more for the knockback than for the damage. It is pretty good damage, but Defender damage scale isn't as inspiring. So I put tripmines in chokepoints, and when enemies rush in, they go flying right back out.
Time Bomb: This is probably really effective if you can figure out how to use it right. It's that big 'if' that's the problem.

I think you guys are missing one of the primary aspects of Triage Beacon.

I prize it for it's strong visible focus. It's a distinctive call for any hero (or villain) for whom health is a concern, saying loudly "Come over here!". That allows you, to a large degree, to dictate the center of the battle. I roll with Heal Other as a compliment, but it helps that any injured heroes always run to my Triage beacon (and therefore to me) so that healing them isn't difficult.

Personally, as a defender, I like being on a team that is consistently challenged. On difficult mobs, I prefer to follow a tanker's leap into combat pretty closely, and Triage beacon is the first thing I drop. That, plus my FF Generator following me obediently, is enough to make sure that the tank won't fall. From there, Acid Mortar to weaken them, poison to give em pause, and caltrops to make sure they don't run away (I put a range enhancer in it, like someone else suggested, and place it behind enemies).

Keys to PGT: Stealth (A stealth IO is enough, but more isn't wasted), Caltrops, and Defense.

Slower teams:
Caltrops, PGT, and optional Trip Mine such that Caltrops fills the area between you and the closest enemy.
Seekers and Mortar, Then blast them to bitty bits as they come at you.
If you do it right they'll mostly be debuffed and mostly be caught in the caltrop field and PGT radius.

Fast Teams, it varies.
Seekers and follow the tank in: PGT, Optional but Reccomended Mortar, Optional Caltrops (use with care, order and effect varies), and Trip Mine. The PGT hold if slotted with something like lockdown, combined with Mortar slotted with the hold proc will hold most if not the entire spawn just long enough for you to get the trip mine off. It gets Criminal if another trapper or controller is along for the ride. If you're fighting stuff with burn patches, caltrops, or other annoyance, skip the mine and just shoot them, they won't live that long anyway.

PGT without a IO sets or som Franken Slotting, isn't as useful.

My #1 cause of death is the FFG getting stuck, lost, or just 2 feet too far away.

Aleyne - Traps/Dark/Power Tankfender Build Not that I'd actually recommend following my build, but it might give you some ideas you could apply to Traps/Sonic.

Related question: Ideal slotting for Seeker Drones assuming level 30ish set IOs? Do I frankenslott for max X or Y? Or simply stack a set for the +Rech or +def? Never really tested the accuracy / stun / debuff of it, so not sure how worth it would be. Now my lowlie level 27 (I think) has 2 Rech, 1 Acc, 1 Rech/Acc.

Personally, I'd slot it for recharge, then slot for any other bonus you want, as long as you get some recharge in it, there are no bad choices, only varying degrees of good choices. It has base accuracy, so more accuracy is good, I'd put 2 acc, but depending on the rest of your build and how you want to use seekers, accuracy may or may not be required. Even unslotted with nothing but a generic recharge, it's still a useful power, just not "as useful".

As I recall, seekers is a 20% chance to stun (I checked mids, mids has it marked 25%). My build is defense oriented and doesn't use any stuns, so that alone isn't enough to make me want to slot any stun. Sure, that might be half the spawn once both hit, but that's still not enough to really make me, with a defense based build, want to slot for stun. On the other hand, if you have a stun heavy build or team, that extra stun could be very valuable in adding magnitude for locking down bosses. IE: Dark Pit + Seekers.

The -to-hit is 10%, enhanced that's 15% for 30 seconds or so (Mids has it marked as 40 seconds). That's the same as an additional 15% defense vs any of the targets that get debuffed. Well placed that can be most of the spawn. 15% defense is nothing to be laughed at. It's marked as unstackable, but since they are pets I'd have to test to see if it stacks or not (it wasn't an issue to me). Given decent recharge, it's not impossible to keep this going fairly steady, and given the duration, it's not impossible to simply have the fight wrapped up that quickly too.

Seeker Drone Slotting: I've got three Stupefys and a raw Recharge in mine. Focus is on accuracy and recharge. The stun is nothing to write home about, the -tohit is okay but not worth slotting. The main goal is to have it up every 50 seconds or so (one spawn) and have it strike home accurately. That -26% damage debuff is godly, and the alpha soak is critical too.

Triage Beacon: I'll advocate this power. It's not used every fight, but it makes a great panic switch. You know the T-junction in a smooth caves map where you can't help but aggro spawns to the left and right? Triage. Keeps the fight rolling and keeps your team from being ground into the dirt in a prolonged battle. Same goes for EBs, AVs, or any other tightly packed space. Slot for three heals, add recharge to taste; you want it available when things are about to go downhill, but presumably that won't happen too often.

Traps is a terrific defender set. Def numbers mean you're pumping out some strong debuffs (put an Achilles in Acid Mortar for extra giggles) and strong buffs. Working duo, even before I17's damage boost to defenders, I'm able to work with a scrapper to take down archvillains thanks to my debuffs... I can cut down on incoming damage with seekers (and with dual pistol's chemical ammo!), debuff their damage resistance with mortar, keep my partner alive with triage, keep them bubbled with ffgen, and spam web grenades to lower the enemy's recharge. And using Traps on my MM, I was able to provide a terrific hardened defense point to take down the entire freedom phalanx from in the LRSF. Glorious.

Don't forget the -regen and -rech from Poison Trap. Though it's not on all the time, when it is on the debuff is extremely powerful. With 50% uptime, Poison Trap effectively halves AV/GM regeneration.

As a plant dom I always found it frustrating when people would skip triage. I know 300% isn't always especially noticeable, but they do stack, and it becomes extremely helpful when you have multiple regen effects active, be it from a spirit tree, second triage, an emp's aura, etc.

Dahjee its good but its not that good

Procs are definately nice in acid mortar in particular though since each mortar has a chance to apply the proc.

Web Grenade I wouldnt rely on the hold proc too much and the slow effect from slotting in there is kinda pointless, however web grenade is still a very nice power to have for those 'oh *bleep*' moments when a boss gets past caltrops.

Caltrops however is much better and more reliable since it can hit multiple mobs and have a chance to proc on each damage DoT per mob so all the procs you can slot here are nice.

As I mentioned in a previous thread, poison trap use depends on playstyle, i personally dont use it, although i used to until i found i only really needed it for AV's.

Your idea for Sirens Song/Dreadful Wail/Time bomb does work though, very well too as I have seen. However on higher difficulty settings this still isnt enough to kill a mob off because of defenders damage with the powers. More often than not you will do this then get bumrushed by whatevers left. However if you do this tactic then consider seeker drones for whatever survives the blast so you can limit the leftover attacks damage since you will already be in the middle of the mob, then jump back and spam howl and shockwave until mobs dead

Are you certain caltrops procs every tick ? That would be 46 procs per target in 15 seconds. Most powers of that type are supposed to proc once every 10 seconds, or 2 procs per target for the entire duration of the power for a 15 second power. If it's proc-ing 46 times per target, that is (46 * .2 * 72) + (46 * .2 * 72) = 1300 damage per target in 15 seconds, that would most certainly be a bug. If it is proc-ing more often than 2 procs per target per 15 seconds, it should be /bugged.

He is mistaken.

Patch type powers with continuing effects roll once at the beginning and then once every 10 secs for the duration of the effects. Caltrops lasts 45 seconds which will yield 5 chances to proc throughout its duration.