A lot of people want to say BB because it has the Ski Patrol area. I 100% agree it's a great kids area, fantastic. But TL has a really nice kids area too. It also has plenty of fun slides. Yeah, the wave pool is a monster, but it's an awesome one. We've had our kids in it since they were really little. It's a zero entry pool, so you can have them go in literally 6" deep water if you want and by time the wave gets there, it has a lot less power. Yes, the floor is rough, we've all had skinned knees or elbows, but not a big deal. There's also a fun little kids area right off the side of the wave pool, so that waves come through there as very gentle ones.
So what I'm saying is that frankly they're both great for a 5 year old. I pretty much like them equally, so you will pick the "right" answer either way.