some points for the OP
Rad/Rad is very good solo BUT you need to corner pull with your toggle debuffs. You pull with Rad infect.
Rad Blast dps is low and the set has many slow activations. It can be proc'd reasonably well. And with Rad Infect you will hit stuff.
Toggle Aura debuffs are rough to use on teams. You end up either taking the alpha strike or putting the debuffs on late after someone else broke the spawn.
Choking Cloud isn't a required power and personally I never ran it.
Some people above seem to think that Rad Infect main power is -def but it does give -tohit as well which means you are helping the team stay alive. The issue is that to use Rad Emission well means going relatively slow, corner pulling, working with the team, etc. I haven't had a team do this on homecomin, but on live in the hollows arc I used to experience this a lot.
Rad Emission does have some real benefits. Take Fallout and vengeance, and teleport other. When you get someone who runs off and dies just teleport them to the main group, hit vengeance and then use their body to blow up spawns.
EF and Lingering radiation are absolutely amazing for AVs, GMs, etc
The purple patch really hits Rad Emission hard.