I also vote for BB. We tried them both last June with 3 kids, DS-9, DD-5, and DS-2 (almost 3 at the time.) BB is great because they have a preschool area plus a Jr. Ski Patrol area specifically intended for 5-12 year olds. Additionally, both the 9 year old and 5 year old found plenty of slides they enjoyed ourside of the kids' areas (and neither if particularly adventurous or a strong swimmer.) I think they've done a great job at providing something for everyone. The family raft ride at BB is absolutely great too.
Although we'd always loved BB, we tried TL too because we'd also heard nice things about that. The wave pool was definitely bigger/nicer, the landscaping is nicer, and there was lots of sand to dig in, but we were disappointed in the preschool area. It was too tame for most preschoolers/early grade schoolers yet too much for our 2 year old.....virtually every slide had an area where water would spray in the face of a toddler/preschooler. The general kids area had a nice themed ship, but there were lots of jets of water that kids could direct, so just when my 2 year old would find a seamingly 'safe' place to play, he'd get 'shot down' by a big kid. (Certainly didn't hurt him, but didn't make him very comfortable either.) I eventually just went and bought him a bucket and shovel so he could sit by the side of the wave pool and dig.
We loved BB though.....seems they have a slide for just about everybody from early Toddlers through Adults.