Conversion time from AVI h264 to imovie or FCE

Hi, I'm close to buying a new (2011) MacBook Pro 15"m 4 GB Ram, 2.0 Ghz computer, but I do all my video shooting with a Creative Labs VADO camera - i.e, h264 AVI files. I'm nervous about the conversion time to make the file editable in iMovie and then, if iMovie doesn't quite do it, I'll probably graduate to FCE.

My question really boils down to this: How much hassle and time is the conversion? I would typically have an 90 minute videos.

Before I plunk down $2000 I want to make sure this works! Thanks