Quicktime can't touch WMV.
If you want to know what WMV can really do, download this clip from my server. 7:23 and 45.9 megs, making it about 2.08 megs per 20 second clip.... gallery level encoding.
I encoded it myself using a program I wrote to deal directly with the encoder.
All the encoding software currently out for WMV is garbage so I wrote my own. There's options and features that simply can't be set even with Windows Media Encoder itself.
Remember, this is encoded at gallery level, 2 megs for every 20 seconds. Check it out.
I used a DVD as the source, as that will show the greatest loss.
Video is 720x480, with stereo sound at 48K.
I am confident in saying it'll beat Xvid, DivX, Quicktime or any other codec you can think of for quality to bitrate. Anyone who thinks otherwise, I'd be glad to challenge to a taste test
http://www.fullscreenvids.com/suabm12.wmv
Edit: please right click, save as... It'll make browsing around the keyframes a lot faster.
-Alex