I have it. I didn't have any of the other older versions though so I really can't compare it. HOWEVER, one thing i did notice right off the bat is that it is terrible for importing clips from various formats. For example, I had a few clips that were in .mp4 format and the video and sound was very jumpy/choppy. I then converted to HD WMV and Vegas struggled with the large file format. The file formats that have worked flawlessly for me are: .avi and .mgp...other than that I need to convert using 3rd party software.
Also, I have a dell xps, core i7 2630qm quad core @ 2.0 ghz - 2.8 w/turbo boost, 6gb ram, nvidia GT 540m w/1gb ddr3, WIN HP 7 64bit and was told that my computer is a bit too slow for Vegas. I was like wtf. But apparently the core number past two doesn't matter and the clock speed is what you should be concerned about b/c Sony suggests a 2.8ghz minimum for Vegas. I KNOW the RAM amount past 3.5 doesn't matter either b/c the software is only 32bit but a 2630m being too slow kinda hurt a little inside....
Well anyways, those are my two cents. If you have any other particular questions feel free to ask! Make sure your system can run vegas or else you'll be disappointed at the speed. My computer takes a few hours to render 40min HD video.... Maybe someone here can help me improve this.
My conclusion is that the following is preventing the rendering from being faster:
1-My corei7 clock speed is lower than the minimum recommended 2.8 ("minimum".....WTF....)
2- the fact that Studio is 32bit....
3-......
Don't bother looking for Studio 10 64bits...it isn't made.