John - it's great that the ClipWrap guys have made it so you can rewrap the 1080p60 H264 file within those MTS files into Quicktime movies (m4v or mov) that you be imported successfully into FCPX. Previously most users here found that it just didn't work, typically the video was black. This is very exciting for users of other cameras as well. Note that it is fast because all that happens is that the H264 files within the MTS container are just copied and put into a QuickTime container. There is NO transcoding with this approach, and that's what makes it so fast. This is what is meant by rewrapping the H264 file.
Now when you say you can see the thumbnails in the timeline, that means FCPX has imported the H264 movie into an event and you can put it into a project. FCPX will have put a copy of the movie into your event under originals - you can find it there now, assuming the preference is to copy, rather than leave in place. If your mac can actually play back 1080p60 H264 like this within FCPX or quicktime, then you're lucky. If it can't then you should choose to transcode on import to ProRes or Proxy ProRes, and get FCPX to use that format on playback, which will be much less CPU intensive. On export FCPX will make a movie according to the settings selected *from your originals*, so it doesn't matter much if you use proxy files to edit with. There will be no loss of quality at all either way, apart from the re-encoding to the final export format, and that is inevitable depending on the codec.
Interlaced video is a huge topic and I've written a number of posts about it previously. I don't have time really to repeat everything I've said. Interlaced video is intended for TV playback and is a compromise to the bandwidth/quality tradeoff that makes sense on TV's - but really doesn't play so well on computer. I too have a 1080i60 camera that will not do 1080p60, but mine will also do 720p60, and I bet yours will too. You will find that when you export for computer playback, you will need to deal with interlacing issues. There are a number of ways of solving the problem. If you're output format is intended to fit on iPad and iPhone retina displays, and also actually within most laptop screens, then you can set the project to 960x540 and FCPX will on export use every second line, removing all interlacing artefacts. If you want full 1080 output then you'll need to consider your deinterlacing options. You'll learn more about this later, and will need to experiment a bit depending on what the output format is. Long and short is that it can be deinterlaced to 1080p30 or even 1080p60, and what you do depends on the amount of motion and information in the video, you can use adaptive or simple blend algorithms; good adaptive algorithms give great results but a lot of CPU is needed; you would normally do your deinterlacing on an exported ProRes file after you finished the project. Adaptive 1080p60 deinterlacing from a 1080i60 original is as far as I know only an option in JES Deinterlacer; this is the only way to retain all the motion detail of the 1080i60 original - if you deinterlace to 1080p30 either there will be blurring (in blend mode) or frame to frame jerkiness (in adaptive mode). If you've shot the video with a shutter speed of 1/60 then you'll have good tidy motion blur and you will get fabulous results deinterlacing up to 1080p60 from 1080i60.
Truthfully however 1080p60 is currently state of the art if you want to play your stuff back on large screen TV's with smooth motion.
Your camera will certainly support 1080p24 and that will look good too, without interlacing issues, though it will be a bit more jerky because there will be greater frame to frame differences.
Anyhow, you're at the beginning of the Great Video Adventure. FCPX is great; very quickly you'll find that FCPX isn't the problem - the real challenge is understanding all the technology that it puts at your disposal, and the technical trade-offs - oh, and yes, then the art of cinematography as well!
chris
