I'm a member of BJA, along with BJ21, BJtheforum, Blakcjack science and recently this site. I also read the forum from a blackjack gambling forum. I'm still trying to figure out how all these sites are connected since I see many of the same posters on the different sites. I sometimes wonder why a person posts on one site rather than another. It appears like BJtheforum is the most activity and has the most knowledgeable bj players.
I've found BJA very good and worth the money, at least for me. But then again, I learn something from all bj sites. This might not be true for the experienced bj player but I'm still new to this.
One of the big values on the BJA site is all the podcasts. I've found these very good! I listen to them on the way to casinos, especially when I'm driving for several hours. I've learned a lot from these podcasts, and they're entertaining! Colin does an excellent job with his interviews. If for no other reason, I'd recommend BJA just for the podcasts, but the forum is good too..and active.
Btw, I've found ZeeBara posts very good, as well as entertaining, especially all the responses. He asks a lot of questions I've thought about asking but too scared to ask. I'm still learning too but feel like I've come a long way in the last year, with the help of all the experts on these bj sites. It's a great community!