Sonic/Sonic - skippable powers?

So I made this awesome and not so expensive build for my son/son, the only defender I have. He's still 20 and DO'ed but I already like him very much. I'll post the build if you want later because I'm on Mac OS X right now.

But I have some questions:

1) I skipped Sonic Siphon - I put out so much -res with my blasts it didn't seem needed. What do you think? I wouldn't have skipped it if I weren't Sonic Blast.

2) Shout - I got it, but... Although I don't have recharge in my attacks, I can already chain Shriek, Scream and Howl quite well (of course there's a pause but that will probably be gone with SOs and more slots) - that would free up slots for other stuff. Is it worth it? I saw the -res lasts more, and later I'm getting Screech anyway. Does Shout lower my dps? Is it beneficial for harder targets since this is a teaming only toon or am I better investing in the t1-t2 chain with screech whenever it's up?

3) What do you usually slot for Liquefy? I went with some acc tohitdebuff set for defense bonuses but it doesn't max out the recharge. I don't know how good this power is to warrant maxing out the rech since it's almost nuke level (300 versus 360 secs).

Thanks in advance.

1). Skipping Siphon isn't the worst thing in the world. I view it as a 1-slot wonder that does have uses. The 30 second duration makes it useful for AVs. I definitely don't use it in regular mob fights, but personally I think it has too much utility for AV fights to skip.

2). Howl, Shriek, Scream and Screech (and sometimes Sonic Siphon) keep me busy. I'm in the "anti Shout" club, at least for a mature build.

3) I say make Liquefy work for you. By that I mean slot it with whatever helps your build goals. My priority was soft-capping range def so I went for 6 slotting Cloud Senses, a very nice set indeed.

Please do not skip sonic siphon, or else I will die a little on the inside.

I would skip Shout and take Siphon. Yeah it might be overkill against a single target, but there are situations where you want to spread the -res love around beyond your primary target, and the duration on it means you can do so fairly effectively. Tag Siege with Siphon while you blast Nightstar, for example.

I'm a big fan of Liquefy. The recharge is a bit long for what it does, but I look at it as a mini crashless godmode. Against most things that don't resist -tohit, it can effectively softcap you, or damn near. I like to use it when I'm soloing a crate in the Lambda trial. I can tell a huge difference in the amount of incoming damage once it expires. Unless you'll be incarnate softcapped to all positions or types, you'll find good use for it. Even if you are there are times it can save your team. As for sets it depends on the build and what bonuses I'm chasing. I've slotted Dark Watcher's Despair, Analyze Weakness, Cloud Senses, and Basilisk Gaze. Probably some others too but those are the only ones I see after glancing at a few builds.

Edit: You might have noticed that yeah, I have quite a few Sonic Resonance toons. Now that I think of it, I have more of those than any other buff/debuff set.

Sonic siphon is -30% resistance instead of -20 like your blasts, and it lasts 30 seconds while the blasts last 5-10. And it requires no extra slots. You want it. Just keep in mind that it doesn't stack with itself, unlike the blasts.

You also want shout, simply because ranged sets are the best set bonuses you can get, and you can't make a full attack chain out of shriek and scream alone.

Yes, slotting liquefy for tohit debuff is the right choice.

I fall into the Anti-Shout crowd. If you really want a third blast to chain with Shriek/Scream, I usually dip into the Epic pools. I went with Electric Fence - surprisingly good damage, takes a damage proc, and it immobilizes those I AM RUNNING NAO AVs.

Shriek/Scream/Electric Fence or Shriek/Scream/Shriek/EF are both solid chains that should beat out anything with Shout.

There's no such thing as too much -res (until you reach the cap which is a rather rare event).

Using my own build, I did 2 30 second simulations of an attack chain of Screech>Shriek>Scream>Shriek>Shriek>Scream>Shriek. One simulation included Sonic Siphon, the other did not. The one with Siphon produced almost 15% more damage over those 30 seconds than not including it. Your team's total damage would obviously be higher with Siphon included. I will not be showing the details of my work because there may be erroneous particulars I don't want nit-picked, but I'm satisfied that the "big picture" is accurate.

I do want to re-emphasize that Shout is NOT needed in an attack chain with decent recharge. With Howl, Screech, Siphon or even Dominate (my epic hold) there's never a moment waiting for a blast to recharge.

*None of the above accounts for Arcannatime.

As for the build above, I had these thoughts:

If 4 slotting Stamina, 4 pieces of Performance Shifter will give you basically the same numbers for Stamina, but with some decent bonuses.

If you're taking Siren's Song, might as well get Fortunata Hypnosis, the purple set that's always in the clearance bin. Yes, it's more expensive than Sandman but still probably cheaper as a full set than some of the items in this build.

You mentioned going overboard for recovery, I went for the Cardiac alpha (which boosts resists as well) and find endurance is well taken care of, that's without any +end boost like Power Sink.. That may allow you to rethink some slotting.

ETA - also, if you're looking for a Steadfast unique, Tough would be a good spot. With no resistance slotting at all in Tough, you're hard-capped to s/l damage. I'd take out the Karma -kb, add in the Steadfast -kb into Tough and now you have 2-3 slots to play with.