For what it's worth...

The dual pass in wm8 was cool if you were going with a relatively high bitrate, or squezzing something realy small. Otherwise it had a tendancy to cut the bitrate so much that sections of the video looked pretty nasty.

The dual pass vbr in wm9's encoder is *GREAT*, though it's one of those you want to consider rendering overnight with - it is slow at full size, not too bad at 1/2 (320 x 240). It has a quality vbr option which is less bit rate sensitive, and a peak vbr that limits how low it'll cut things, and what the maximum (peak) bit rate will be. After a 7 hour render or so, I've gotten just over an hour's worth of full size video at 30fps on a CD, & you'd be really hard pressed to tell it from the digital original. The downside is wm9 vbr takes a heftier cpu to play it back, older machines don't like it.

What's really cool is that wm9 is editable! You can treat it like an avi file -- only the part that changes gets re-rendered/re-compressed! Playing with wm9 captures there seems less quality loss per generation then working with comparible avi files, disk space is almost irrelevant -- just need more then a junior editor like moviemaker 2.

mike