I have a couple of different BF444 cards. If you can get the Summetry capture/print app working on your machine (a work in progress but has alot of promise), you can, in Vegas, edit and render to the BF file format with ease. As of right now, you don't get totally comprehensive HD support with any Vegas/BF combo, but it does work, is very cost effective, and the output quality is excellent.

You need a monster machine (see the BF site for requirements) and of course you need an HD deck, monitor, and camera, scope, raids... you knew that.