It's interesting how so many threads tend to derail into the same direction of "Incarnates and heavily IOd builds makes the game less interesting"... I can't say I disagree with those statements.
But back on the subject opened, I definitely agree with the feeling around toggle debuts. I never actually played a radiation emission character on live, but I decided to roll one in Homecoming. I had always heard about rad being so amazing and tide turning... but I was actually disappointed in the performance of the character for the same reasons you mentioned. I feel like crowds are melted and dispersed and the debuts make no difference.
I've had to make a couple of shifts to keep things interesting for myself. I only really bring the character out to do task force/ strike force content, trials, and anything else where there's a single or several really tough targets. If I bring her out in PUGs, I just feel like a subpar blaster with a paltry heal.
All that to say... I think it would be less frustrating if the debuffs were not toggle and just were powers to fire off. If the idea is to prevent a single player from applying the same debuff more than once to a particular target, I'd hope some clever coding could angle around that and keep things balanced. I realize the ability to apply the same debuff to more than one target might be an issue, but I am confident that minds steeped in the arena could figure out ways to prevent something game breaking there too.
Troya