This is tough...
BB has a great kids area. Actually two areas. The first is for kid's around 5 and under (IMO). The other is for kids 5 to 11-12(?). Very well themed. The only negative for me is that BB I find to be much busier than TL.
TL has a really good area for your age kids. The other plus is the wave pool and beach. While you wouldn't want your kids out in the deep part of the wave pool, the shallow area and the sandy beach are great. Last, I think that you will find that TL is a little more relaxed than BB is. Also, I think that TL is easier to find your way around than BB.
Overall we go to both (kids were 6, 9, and 11) on the last trip. Our six year old skipped the little kids area at BB.
Hope this helps,
Greg