I have clipons. I don't use them in group rides. Because the clip ons don't have brakes on them, so you have to switch positions to suddenly break. And the bike feels a bit more squirrely when you're in the center as opposed to steering in the drops.

It takes me 5 minutes to screw on my bars, so I usually only do it a few times before a tri to get used to the position again.

I think it's really a comfy position, personally, but don't see the need of it even for long rides. I find the drops just as comfy.