I've found rendering to Uncompressed RGB / Uncompressed PCM for audio/video from Premiere saves me alot of time, and lets me experiment with compression in VirtualDub instead. Sound, for example, need only be compressed once this way, using direct stream copy for any adjustments on video compression later.
Yup, that's also how I always make my movies too. Export a totally raw movie with uncompressed video and audio, import it to vdub, compress with DivX and Mp3 (with suggested bitrates) and off ya go.
Yep, found out that too.. It saves really much time, rendering in Vegas takes as long as it used too, but then the compressing in Virtualdub goes much faster than rendering again to check filesize in Vegas.