Any thoughts on this? Does CBR make the most sense?

Depends on the bitrate. If you use max, it makes no difference.

Does CBR make the most sense?

Only if you can max the bit rate. If not, any really fast scene/contrast/any other image changes could overrun a lower bit rate and hurt quality.

I generally use VBR-1 pass to handle any spikes in the data rate. If I see anything untoward, I'll run it again with 2 pass.

For videos 60 minutes and under I just set it to CBR 1-pass 6300kbps and forget it. Footage looks beautiful...no issues with crossfades/whatnot.

Ive found my best pictures, including crossfades, animation effects and such comes with a two pass render.

Essentially its 8mbps max, 6mbps min and average, two pass.

I was doing a CBR, and found image degredation in the effects, such as a title fading in/out, but fine on general vision.

The biggest secret was to render the whole project to an .avi file first, THEN render that new one to MPEG2.

Doing that saves time. Doing the two pass render keeps the quality.

Ben