When I bought a rack years ago, I loved being able to shift the toms even an inch or two to the left, so you can see THIS:
Then, I started playing a lot with a four piece kit, and really loved being able to pull the ride in close. When I bought my new-ish GMS kit, I tried going whole hog, and ended up loving it:
(Hmm... I need some newer pics since I changed heads...)
I love the interaction between the two rack toms and the snare. Makes for a lot of combinations that I wouldn't have thought of with a standard 5 piece setup. The only downside is that it forces my hi hat to be a little too far back. The solution is a compromise- slide the toms forward a bit, and my hats are still a little farther back than I'd prefer... but the advantages far outweigh the compromises.
For what it's worth, I don't double bass, and I like my hats as close as possible.