Your machine will be very sluggish with AVCHD, especially if your using the 1080 60p. You will also have to make custom project settings to use 60p. For editing purposes though, I would convert the .mts files to DV widescreen, edit with these as they will edit easy on your machine. Then just before rendering, set your project settings to your custom 1080 60p preset, replace the DV widescreen DV files with the .mts files and render. Right before you go to bed. LOL