Help me choose my ill/rad's APP

Yep . . . and I have tried all of the APP sets with my Ill/Rad. My recommendations are first, Fire, then Ice. I'd rank Primal next, then Psi with Earth last. If you have not read my Illusion/Radiation guide (linked in my sig), most of the points made below are in the guide.

The most important thing to me is that quick single target blast. Illusion is built for distracting groups while taking foes down one at a time. Illusion is not great at setting up Containment on groups, so AoE damage is less important. Plus, to gain benefit from the Illusory Damage in Spectral Wounds and Phantom Army (and Phanty's Decoy), you want to take down those single foes fast. That Illusory Damage heals back after a few seconds, but if you can defeat the foe before the heal-back, you get to keep the damage. That can substantially increase the amount of damage you do. So you want fast damage without a lot of Damage Over Time.

You also want a fast recharging single target blast -- because you can get that fast damage with the Blind-SW-Blast-SW attack chain. That's why I don't recommend Earth because Hurl Boulder is too slow.

Another consideration is damage type. Illusion is all Psi damage except for Phantasm's blasts. Psi is heavily resisted by some foes in the late game, like Robots -- and you see lots of robots. Getting a different Damage type will help you take those foes down more quickly. That drops Psi down the list.

Fire Blast does the most damage of any of the single target blasts, except for the slow Hurl Boulder. It adds a bit of DoT after the initial blast. Fire and Ice also activate slightly faster than Primal and Psi. Fire and Ice are rarely resisted damage types.

Then look at the rest of the sets. Fireball is mostly fast, up front damage, with a little bit of DoT. And it activates quickly. Ice has two AoEs, Frostbreath is a cone, so it requires positioning and hits fewer foes, while Ice Storm is a location-targetted AoE with all of its damage coming over time (letting the Illusory damage heal back) and with a long Recharge. So, for Damage only, I think Fire is better by a little bit. However, if you want a Defense-based shield, Ice can then be a great choice. You can also consider the usefulness of Hibernation vs. Rise of the Phoenix and/or Consume. Fire's Resistance-based shield is OK and can help reduce the damage you take, but it is not the reason to take the set.

Primal has a good but slightly slower single target blast, a resistance-based shield, Conserve Power and the key power, Power Boost. However, Illusion doesn't have that many powers that will gain from Power Boost -- compare it to Mind Control, which has many. Primal's only AoE damage is a cone, with the limitations of a cone.

If you are getting Mezzed a lot (and you shouldn't be), then Psi is worth considering for Indomidible Will. Psi Blast is slightly slower, like Primal's. Psi Tornado is a nice power, but it is all Damage Over Time, giving more time for that Illusory Damage to heal back. And there is the problem of damage type. The Resistance Shield is OK, and on the plus side, IW and Mind Over Body provide some Psi Defense and Resistance. On the downside, the last power, World of Confusion, stinks.

Earth is great for Melee types, with the very short range Fissure and Seismic Smash. But I play my Ill/Rad at range, as part of his protection. Earth has a good, but ugly, defensive shield and a great heal/HP boost, but the damage powers just don't fit.

I can't help you much with the PPP powers . . . concept-wise, my Ill/Rad just can't go Red-side. But I know none of the Villain PPP sets have a single target blast that recharges quickly enough for the Blind-SW-Blast-SW chain. You need a recharge when fully slotted of 4 seconds or less. Mace has Poisonous Ray, which is the closest thing at about 6 seconds. A few people have said that they wanted to go that direction. I have yet to hear from anyone who had the fast Blast first, then tried Poisonous Ray and thought Poisonous Ray was better.

Another perma-pet is certainly appealing, but I don't really need Defense. A perma-PA build is built around pulling the aggro of foes to the PA and Phanty's Decoy, so they should be drawing the attacks, not you. Some folks believe that the -Resistance in Poisonous Ray will make up for lesser damage due to a slower recharge, but to me the key is trying to reduce the heal-back by getting fast damage.

I'm also not sure how the time spent drawing the mace will affect your damage.

The one time I have done the Apex TF with my Ill/Rad, we had 66 deaths, and only 4 of them were mine. The soft-capped guys died a lot more than I did. That indicates to me that Defense is not really a priority.

I too went mace for the shield and the pet. My attack chain is almost non-existent but it doesn't need to be with Toxie, Phanty, the boys, and scary boo

I was shocked at the masses he could handle when I tried to solo the 4th mission of the alpha arc on my defender and failed, fired up my 2nd account grabbed my ill/rad and went in to help, by this time the 4 portal spawns were huge, but I managed to clear the whole room w/o a face plant. even tho I was taking a lot of agro as even PA had agro cap issues in that room.

my play style isn't focused so much on my DPS, rather I go the confuse to soften, Pets to mop up route.
However, if I were ever inclined to solo an AV, I'd go fire

To be fair, defense doesn't make a difference to the Insta-Kill patch of death.

I would suggest that too. Plus on a perma PA Ill/Rad you don't need status protection.

Accelerate Metabolsm shortens the duration of Mez, but does not protect you from it. But with your various controls like PA, Spectral Terror, Deceive, Blind and Phanty and his Decoy, and use of Invisibily, you shouldn't be getting mezzed much unless you really like an aggressive play style. As long as I stay away from the AoE mez powers, I rarely get mezzed on my Ill/Rad.

While everyone's playstyle is a little different even with the same powersets, the only time I have to even consider getting mezzed is when I choose to (for whatever reason) jump into the fight and drop flash or em pulse. While I have both of those powers on my Ill/rad as panic buttons, primarily between Perma PA, Spooky, Phanty, Blind, Deceive, etc I am staying well out of range. Couple that with a cardiac core boost for endurance/range boost I can stay even farther out of the fight. Indom Will sounds to me to be better on something that sticks closer to the combat, like a fire/kin or Plant. Unless you really like to mix it up, (like running in with choking cloud and using flash/em pulse etc, I really dont think you will need Indom Will and should IMO go with fire. On a Perma PA Ill/rad I was able to sneak in rise of the phoenix and with that much global recharge it is available whenever your need it. Like in my MoApex run where I was able to just pop right back up in fighting shape whenever i got stuck in an animation when the blue patches of doom caught me. (sigh that was a fun fight....)