Premiere Pro: H264 v ProRes

Hello. Long time reader, first time poster. I work at a post-production company who are contemplating moving from FCP7 to Premiere. This is due to FCPX not really coming up to the standard we expected and the fact we already use AE and Photoshop for our graphics. It does make sense in the long run.
I am a long-time FCP editor. I have used it all my working life. In the last two years we have moved over to a Canon/DSLR workflow where the camera records H264's and we then capture them as ProRes. But with the move to Premiere this workflow maybe in doubt.

My questions are these.
Is there any advantage in editing with native H264 vs ProRes (captured from H264) in terms of colour space, using in AE, playback and quality?
If not H264 and not ProRes is there another codec we can capture into that works as well as ProRes works in FCP?

In my own experience H264 is a final format to deliver to clients and not a format to edit with, however, I do realize this is due to being a FCP editor and FCP being unable to handle the format well.

I have read a few forums and have the feeling its down to a preference thing and what you are comfortable with. It really has split opinions in our office. I am not 100% sure I will get a definitive answer but any views would be great.

Hi Paul. We were very happy with FCP 7 editing Canon DSLR footage .... bit I have to tell you, at first I was very reluctant to try FCPX .... but now I love it. It's wicked fast, automatically encodes our DSLR footage to ProRes 422 upon import .... and is very stable on the iMac with Pegasus thunderbolt drives. I'd suggest you I've it a try before you bail to Premiere .. You might be surprised. Good luck. BW