I have been one of the folks that has had issues with Vegas 9. Poor timeline performance and poor playback were among the issues I have had.

Vegas 9.0c seems better though still not responsive as 8. It doesn't get a mild "buy" recommendation from me as it is still a tad glitchy for me. The support for high rez photos really only seems to be a minor improvement in the handling of photos, as I still find it necessary to resize photos anyway for acceptable performance with panning and scanning. I do admit that a project I rendered in Vegas 9 actually came out improved over a version of 8, a tad more detail in a couple of shots.

What is mystifying is I still find I get better rendering times with version 8 32 bit than with version 9 64 bit. (FWIW, I have a relatively new machine with gobs of memory and an i7 processor).

So I'm using it now with my new copy of Windows 7 Pro, mainly because I paid for it and it at least does function acceptably (at last).

I've got 9c, it often crashes when I import hdv files. I import to Vegas 6, render to Cineform, then bounce it to Vegas 9.

see my other post.
http://www.dvinfo.net/forum/what-happens-vegas/466630-vegas-pro-9c-update-problem-magic-bullet-looks.html

I just installed 32 bit version of 9, it actually renders faster for me....weird.

I haven’t yet upgraded from 8.0c yet due to problems everyone seems to be having but I have just bought a nanoFlash and I need to upgrade to 9.0c so that I can edit i-frames. 8.0c edits that Long GoP well but not i-frames.

My version of 8.0c worked will in 64-bit and was going to load 9.0c in 64-bit too but not sure what to do now! Does MB work in 64-bit with 9.0c?