I play DBA. I tried DBM, but found it difficult to learn on my own. I tried DBA to learn some of the concepts, and found I liked it better. Later, DBMM came out, and although I was fairly sure that I was playing it reasonably correctly, I found that I could play the same armies quicker and with more fun.
When I started with DBA, it was version 1.1. Nowadays, I tend play the ‘+’ unofficial amendments to version 2.2. Although I will try version 3 when it is published, I am unlikely to take to it. (I tried an earlier draft of version 3 and didn’t like the new movements.)
Why do I like DBA? It is easy to teach new wargamers, the games don’t take a lot of space, you don’t need big armies so you can paint appropriate enemies as well, and the games are quick, and often exciting. I can get several games in in one session.