I've spent time as both an ABT and PBA member. I certainly enjoyed PBA competition a lot more, but it's much harder to spend $220 + travel/lodging per tournament as opposed to $65 plus pots at ABT. Plus, when ABT was still active in the Chicagoland area (our branch now transitioned to RTB), there were tournaments within an hour or so of my house just about every weekend all year long. Again, this is much different than having to travel 6 plus hours to many PBA events in neighboring states.
I HATE handicap tournaments, and I've never had a ton of success in ABT due to being stuck in the middle. I'm too good to be in the lower division, which offers lower cut scores, more spots, and more money, but I'm not really good enough on Sport to compete with the guys who really at the top tier. As such, I've been a middle-of-the-road ABT player throughout my career there. I've got a 2nd-place finish, a few other Top 5's, and a whole lot of disappointing outings.
I don't like losing to guys who are getting 30-40 pins of cap per game on me, but I know what it is going in, so I don't complain too much. Long story short, if you want to bowl tournaments, ABT is a viable option, but it's far from perfect. Prepare to be frustrated by obvious baggers and, if your branch was anything like mine, the old boys' network deciding who gets re-rated and when.