Honestly my 3 year old boy likes both of them!
At TL of course he liked the Catchakiddie area and got a big kick out of family ride, which was short, bumpy, and SUPER wet. He didnt like the dark tunnels on the lazy river and I felt that the wave pool's waves and current were too strong for small kids.
At BB he also liked the kiddie area, loved that sneezing water house thing on the lazy river (we went back in Sept and he STILL talks about it), wanted to keep riding the ski lift up, and thorougly enjoyed the Looooonnng family ride. "one more time? one more time? one more time?" which turned in to "one more time! one more time!! ONE MORE TIME!!! "
Oh and the kid area has more slides then the TL kid area. HOWEVER, each park has a little kid tube ride in the kid area and at TL (if your boy is scared) you can actually walk the ride in the water next to him or even stand up out of the ride and pretty much stay with him the whole time). At BB you can't be there with them.......you have to run down to the bottom of the hill to be there when he gets there so if he gets scared he's on his own.
I agree that BB has a lot of cement but so does TL. Either way you know your boy is going to get banged up one way or another!! Bring some fun water proof bandaids!

Personally if the weather is warm I say go to both of them!
If you need more info or would like to see pics of the kid area I have them....just PM me and we'll chat more!