FCP can transcode AVC-Intra over to ProRes, or it can rewrap it from an MXF file to a .MOV file. Those are two different things. Rewrapping it keeps the file size the same and keeps the original in its highest-quality form, untouched and un-recompressed, but it probably won't edit as quickly. Transcoding will cause file size inflation and will involve an uncompress/recompress cycle, but going to ProRes will almost certainly make for a speedier edit experience (unless you have an Octo-Core or something, at which point it's probably realtime on both codecs).

I have an 8-core mac so I dont notice any difference in transcoding or re-wrapping as you say Barry.

Quite the informative responses. It seems that there really is a fond following of AVC Intra beyond what Panasonic claims.

Now for a follow up. Using CS4 with a high end quad core and 8 gigs of ram, it is an impossibility to edit in multicam with avchd files. What about multicam with raw AVC Intra files?

Before responding, I now rewrap the files to use multicam but now I am looking to streamline my workflow. Therefor I am sure you can rewrap the intra, but I am looking to eliminate the rewrapping step.