We've done both and liked both, but the wave pool at TL really knocks you around and left all of us with scrapes on our knees. Be aware that the kids area at BB is super strict with 48 inches and under. I was there with my DD2 and DS7 and he could not go down with her because he was too tall. Just warning you to be prepared to split up if you end up with one too tall.
If you don't think you'd use the wave pool or big slides, I like the little kids area at Typhoon Lagoon better. There was sand to play in, a smaller slide (that emptied into the edge of the "lagoon" with the wave pool), spray guns, and a neat tube slide for little ones.
Tough choice. My kids (7, 4 and 2) would say BB, simply for the wave pool.