The A2-300 has a 12" woofer, vs the 10" of the STF-2. The STF-2 is more expensive, and you probably won't get as much output. If HT is your thing, I think you would benefit more from the A2, plus it's cheaper! So, I guess it just comes down to whether or not you want to wait...
However, if you want to spend a little more, check out my thoughts of the A3-300..
http://forums.audioholics.com/forums/showthread.php?t=62558
It only took 2 weeks to get delivered, and the thing has major output. I won't be feeling like I need to upgrade any time soon