iMovie 10 (the Mavericks version) does import 'bare' .mts files if they are 720 or 1080p and up to 60 fps (not sure about interlaced formats ). FCP does as well.
FCP 10.1 is quite similar to iMovie 10 in appearance but has much higher capabilities. You can download a free fully functional trial version from the App store that runs for a month. I did that and then bought it as a Christmas present to myself. It is very easy to transfer projects from iMovie 10 to FCP 10.1 so you can try out both with the same projects and decide whether the extra capabilities are worth $299 to you.
Hi Geoff, after posting I found the trial. I even ordered two books off of Amazon. Pretty excited about the books' arrival. Bummer FCP is $300. I am going to be bummed if I pay for it in 2014 and then FCP does what Adobe did and goes to $9.99 per month. Ha! Anyways, thank you for your reply. FCP sounds very exciting! Can't wait to jump in!
I don't see any sign of Apple moving to a rental scheme. FCP 10.1 was a free upgrade for those who already had FCP 10.0.x. I would expect at least the next 10.1.x updates to be free.
If your books are not very recent be aware that there a quite a number of changes between FCP 10.0 and 10.1.
There's lots of how-to videos and help about FCP on the internet.