I use tubs because I have multiple BPs, but I like them better than tanks for several reasons:
1) because they give the snakes more privacy, which is something they really like. They live in burrows and termite mounds in the wild, so they don't require the verticle space that tanks provide.
2) I used to have tanks, but found them harder to maintain humidity and temps on my cool side would fluctuate more than I would have liked them to with drafts etc.
3) Space is an issue for me so I like the whole rack setup. It works well for my needs.

Tanks are awesome for display animals. I won't argue with you there. Balls aren't very active durring the day however, which is a down side to that. But if you're a night owl, that could be a bonus as well.
That is my take on it.