The only downside to AACW vs CW2 is current forum activity. Most active posters are on the CW2 board. That said, there is a HUGE volume of archived posts about AACW, and a good dedicated wiki that can help with most questions you might have. A lot of CW2 players also have AACW, so though not as easy as CW2, you can probably still find PBEM opponents as well.
If you like and are effective playing AJE and BOA2 you will get a LOT of mileage out of AACW. The game plays great and the AI is actually a bit better than the one that CW2 currently has, (at least IMO) since it had undergone many more iterations of updates and patches than the current CW2 AI has.