We've been enjoying SAB for decades now, and part of what you're reading has some truth and much of it is overblown. Over Easter break, the pool is absolutely going to be popular. But rope drop and wait for an hour to get in? That's probably pretty rare. As for the 8' river? SAB is 3 separate pools - the 'main pool', the lazy river (which is deep), and a more shallow, beach-type pool that our kids have loved over the years. It is most definitely spread out.
If you're concerned about the ages of your kids at this pool, then you might want to wait a year or two. But if you do stay at BCV, you'll also have access to the 'quiet' pool at BCV, and also the quiet pool at BC and YC - plenty of pools to choose from if SAB is a bit much for the kids at this point. Good luck with your decision and have a great trip!