Of course, yet another solution for this matters of editing AVCHD or just regular H.264 footage is to convert it to Motion JPEG... something along the lines of 100Mbps.
The loss of quality is negligible and virtually impossible to detect to the naked eye. The speed during editing/playback is increased ten-fold however, since M-JPEG is nothing but a series of standalone JPG stills on a video container.
THE PROBLEM of course, is to find a free M-JPEG codec that can be used to encode and display your AVCHD footage.
The great advantage is that M-JPEG files are almost universally accepted by all editors.
That's like.. your opinion man