I switched from Premiere 6 to Vegas a couple of years ago.
The three biggest advantages I found Vegas to have over Premiere are 1) Stability, 2) Stability,
3)Stability!
In two years of heavy use, Vegas has crashed on me less than ten times, and most of those occurred as a result of using an indpendent effects plug-in. When I was using Premiere, I expected it to crash at least once a day.