I have never used this feature. But as I am in the middle of a super heavy edit for my company promo, I am finding that my effects are taxing my system on playback, so I wanted to check out the "selective pre-render" feature. IF I understand it (and the three other threads on the forum) this feature will render out whatever you have selected as an avi (or other format). Then the next time you playback that section on the timeline, vegas will play back the pre-rendered section (assuming you changed nothing) thus improving preview playback speed & quality.

Am I understanding that correctly?

If that is how the tool works, then can I go through and select the bits of the project that I know are locked down, and selectively pre-render those and expect vastly improved playback (if I pre-render to uncompressed AVI)? I'm tired of playing back at preview in a tiny 1/2 size window in order to get 30fps playback, so I'm hoping this is a solution, or at least of some benefit.

Yes. That's how it works for me.

However, prerendering is, as you suggest, volatile.

Grazie