Re: Is it better to convert .wav files to .aif for use in FCP 6.0.6?

As long as you're using aif or WAV you're good. If its a different sample rate then you'll simply want to do an item level render on it, which creates an intermediate file that FCP draws on. No different than converting in QT or iTunes, except simpler and less mess of originals and converted clips all over the place to keep track of. Works wonderfully and it's the way the manual suggests doing for about 8 years now.