Can't compare BB and TL - we didn't get to do TL last trip due to lousy weather - but if you do decide to do BB....DO SUMMIT PLUMMIT!!! We were there in November, and because my 9 year old got over his fear of heights and coasters this year, so did I - MY excuse for staying off those rides was gone once he started doing them, the little stinker

. I uttered some very unladylike/undisneylike words at the top, but went with the idea that it would be over in a few seconds - which it was. I LOVED it - even sitting up at the bottom, raising my arms in the air, yelling "I DID IT!" (which the Photopass people got a shot of!) Rode it again afterwards, too!
To be honest, I found Slush Gusher worse - at least with Summit Plummit your butt stays on the slide - with Slush Gusher, you go airborne. I also found the force of the water at the bottom of SG when you're slowing down worse, as well as the wedgie. It really helps to keep your legs crossed.
But a word of warning - remove any and all jewelry - even things you think are safe. The force of the water (on Slush Gusher, I think

) broke my tennis bracelet that I never took off. It must have snapped a link somewhere, because the reason I never took it off was the clasp was too hard to do/undo. And this wasn't a loose bracelet, but fairly tight to my wrist - so it wouldn't have hooked on anything or been loose enough to get a lot of drag from the water. So leave anything you don't want lost in the locker or back at the hotel.
Again, can't compare to TL, but I do know our day at BB was one of the most fun we had during our holiday - if you leave off the lost bracelet, that is!
PS: If you don't like water up your nose, make sure to plug it going down!!