Why do you doubt Ill/Rad would hold your interest? It's an excellent Posi-soloing build, with confusion to reverse the effects of the most disruptive enemies (Spectral Demon Lords, Embalmed, mezzing "Tesla" Clockwork), and psionic damage to tear through Clockwork and Spectrals (who have a 30-40% weakness to psi).
I do like deceive, it's utility is amazing. I just wonder about the lack of reliable AOE control and the ability to set up containment quickly. I haven't played one, so I am basing what I see on mids at level 15. Compared to other sets, it looks like I would be in for a lot of single target fighting and burning through a lot of insps. while I aggro quite a bit. Again, I've never played it, so I may be WAY off base. Maybe Flash is a better hold than it appears.
I am very open to being persuaded with tactics I don't see. So I appreciate the input.
From personal experience, ill/rad didn't hold my interest.
too many "fire and forget" powers, I felt like I wasn't doing anything at all.
I have solo'd a few trollers to 50 and I hate to break it to you, but Illus is the bee's knees pre-32 for a solo or duo player. Yes it lacks the controller-ish feel of aoe goodies, but it makes up for it to the solo'r in big big ways. SI to get around easier, Phantom Army, Deceive is a great hold (when viewed as one vise a xp stealer), did I mention Phantom Army? 
I would suggest illus/rad or Illus/Kin both rock solo.
All that being said, I have not had any issues soloing non Illus, Fire/therm was a ton of fun and Ice/Kin was ok.
Just me 2 cents. Enjoy.
As much as it pains me to say this.
Plant, all the way. Seeds of Confusion will make posi a breeze. AOE confuse lvl 8. Good damage AOE immobilize. Seriously think about that.
Plant/Sonic, is really good
1) Strangler
1) Sonic Siphon (great -res)
2) Roots
4) Entangle (for damage)
6) Hurdle
8) Seeds of Confusion
10) Hasten
12) Users Choice
14) Super Speed
That right there will make soloing posi a breeze. If your rich and can afford a stealth IO for SS. With the stealth IO you can take tp ally at lvl 12. That will allow you and a buddy to whoop [censored] really quick.
The -res from siphon is an impressive 22%. That helps mobs rip themselves apart quicker.
If you got a buddy whose melee the -res aura from sonic helps even more for the synapse runs and beyond.
16) Disruption Field
18) Health
20) Stamina
People sleep on sonic. But it is seriously a set to be looked at. The shields are fantastic (unless you hate the grfx). Its not a healing set but you won't need a heal with it backing up plant. Plus you get a really good power in Sonic Dispersion. Add into that mix Liquefy, which is a great power for the later TFs.
Just a thought for you consider.
Plant is great for Positron.
I wouldn't make that your AV soloing toon, though. I don't know if there are actually any combos other than Ill/Rad that will solo GMs either, but who knows...
Plant is fantastic for AoE and with Seeds, makes Positron TF very easy. Not too much in the area of single target damage though.
I agree with Grimlek, plants Seeds of confusion does WONDERS for a positron. I've done one with my plant/storm, was the most painless posi i've ever run, period!
However...
Plant is an Awesome AoE machine, whats this mean? 10-20... 30 minions? not a problem. Indeed, i have locked down 2 seperate spawns at once that were too close to each other, and, if need be, able to take them out fairly quickly..
But... Single hard targets.. are your sworn enemy!
My plant/storm is OI'ed out, is an amazing mob mauling machine, yet I can barely den't a GM. while I know this is because Storm isn't the most fantastic Debuffing set, it does offer damage, but not enough.
Tried but true.. Ill/rad is a beast for an AV soloer. It might seem a little FoTM but there is a reason for that Not only do you have the wonderfull debuffage of Radiation, but your pets are ranged, and you have the perfect alpha strike taker in Phantom Army.
Maybe take a epic pool to help with the single target damage and your golden.
Having said all that, I have my own question. How would Fire/Rad stack up? or for that matter, Fire/Thermal 
Combat Kangaroos, Justice Server. First 50's
Jirra Roo Plant/Storm/Stone/Musculature Controller
Combat Kangaroo Rifle/Energy/Mace/Spiritual Blaster
Kung Fu Kangaroo Martial Arts/Reflexes/Body/Spiritual Scrapper
Tribal Arc Shield/Elec/Mu/Spiritual Tanker
Thanks all for the different ideas. I'm still tossing around different thoughts on everything but did roll up a Ill/Rad. I'm level 10 right now and have to admit that it is better than I thought it would. The only pains that I have is that I seem to have large gaps in my attack chain and the AOE is a little weak. I do however love the confuse - it seems to help when the confused MOB actually scores a hit (is it me or do they seem to hit me more and often when they aren't confused - probably not - but I am rambling). I just wish I had an Immobilize as well (TA was very appealing, but I like Rad's debuffs). The psi damage vs the clocks, and later the COT specters, is very nice.
I still am tempted to try a Plant\, but since I am soloing most of the time, the DOT and lack of ST damage is very unattractive. I do like the AOE confuse of Seeds for maximum battlefield chaos.
So I guess my next question, if I continue with this hero, is it possible to take on the Synapse TF by myself, or if I duo with a Rad/sonic defender? I know that there a lot of clocks in that one, so I was curious about going through the missions and whether I can actually take on the AV & GM in that one.
Thanks again.
yes confuse is great. especially since you can choose specific target to confuse without agro. my personal favourites are shield generators, tsoo sorcorers and death shamans confuse a shaman, then have him cast pets.. tada 2 husks ready to fight for you! even without confuse
As far as soloing TF's . yes I would say you could solo a synapse. We did one the other day, with 3 tanks mind you, not the most damaging team, and the clockwork king still vaporised like water on a muffler, but the TF as a whole.. will take you some time
Combat Kangaroos, Justice Server. First 50's
Jirra Roo Plant/Storm/Stone/Musculature Controller
Combat Kangaroo Rifle/Energy/Mace/Spiritual Blaster
Kung Fu Kangaroo Martial Arts/Reflexes/Body/Spiritual Scrapper
Tribal Arc Shield/Elec/Mu/Spiritual Tanker
I am trying to come up with a decent hero for running the 'lower level' content and quite possibly something that will keep my interest enough to push through my alt-itis.
I am looking ideally for a Controller that works well mostly solo, with the occasional duo, that can run, for example, the Posi TF. Ideally, I would love to be able to do that solo, but at least a duo. I also have a dream of a character who can actually take on a GM/AV on it's own. I know that Illusion/Rad can do this, but I don't know if it will be able to hold my interest for all the time it will take me to get to 32. I am a casual player, so I prefer a faster pace so I can enjoy the few hours a day I can devote to the game. I usually end up falling back to melee AT, but I always wanted to try the Controller/Defender. I also prefer COH over COV (at least until Going Rogue hits) since I can't stand the constant Longbow missions and the Island's atmosphere.
I had a suggestion for Plant/Rad, which sounds really interesting. Anything else? I ask about the Posi TF mostly because I usually get to early to mid 20's before I start looking elsewhere and I think that TF will be fun to be able to run on my own (being mostly a solo player).
Thanks for all the advice that is offered.