[Peter Van dijk]

I have the same question, a lot of ex-FCP users seem to have to same problem..
It was all so simple. Export using Quicktime, ProRes, that was the master.
Using that to create other smaller versions.

I read a lot that Avid’s DNxHD would be the solution.
But, if I for instance edit 5D’s dslr footage in h.264 (very good of PP that you can edit in native format!), then export master to DNxHD, that masterfile does not playback smooth!
(Above is, editing and exporting on a very powerfull Windows machine, playing the master file in Quicktime)

[Peter Van dijk]

Finally, a solution!

Panasonic released september 5th 2011 a AVCCAM Importer for Mac.
https://eww.pass.panasonic.co.jp/pro-av/support/desk/e/avc_download.htm#avccamip

I can play my 1080/50p recorded clips now in Quicktime, and so can do everything that you want with it.
Drag into FCP bin, cut directly with the MTS, or even better (for me) open in MPEG Streamclip, export selections to ProRes 422 HQ , open that in Cinema, conform to 25fps!