The best way to find out what will work for any person is to compare several codecs and find the one with the least negative effects. If space saving results, fine, but with large hard drives being relatively inexpensive now, saving space is kind of a moot point.
I went to URC training last week and sat between two Apple geeks, both of whom are running Windows 7 (one using a Beta version and the other using the Ready to go version- not available until next year in a final version). They said it's faster, more stable, less of a resource hog and is extremely media-friendly. They work for a company that does a lot of networks as well as A/V and home theaters.