I use Final Cut Pro, Premiere CS4 and Vegas Pro 9, each has their strong and weak points.
FCP and Premiere are big, cumbersome and slow, if I was editing an Indie film or TV show and had all the time in the world to finish I would use FCP first and Premiere second.
But I make porn
and for speed and ease of use you can't beat Vegas, and I find myself falling back on it when it's crunch time and I have a lot of work to get finished in a short amount of time.
I also prefer Vegas for making trailers because it can do something neither FCP or Premiere can do, you can have multiple instances of Vegas open on your desktop and copy and paste between the timelines.
That way you can have a trailer under construction in one Vegas and the source content open in another and switch back and forth between the two (or more)
This is a feature I have found invaluable time and time again, and it's why I'll never completely stop using Vegas