[Oliver Peters] “To work with the C300 footage you have to install their FCP camera plug-in. When you do that, X rewraps the XF codec (basically the same as XDCAM) from MXF to MOV. This rewrapped media is placed into the Library bundle. The codec itself is unchanged and you cannot force a transcode to ProRes. FCP X sees the XF codec as optimized, once it’s rewrapped.”
Yes it does, but I had a project from the XF305 (same codec) that was a very poor editing experience (basically, anything you did to a clip would not playback smoothly until it was rendered). FCPX seems to handle AVCHD much better than XF, so I would recommend a proxy or ProRes transcode like it’s 2010 again.