Are you saying this from actual side by side comparison or from hearsay, I'm guessing the latter.
Because I chose the A5 over the A2 (
when compared directly against each other) because of the 'quality AND quantity'. A2's have a noticeable midbass hump which is much less prevalent (but still there) on the A5. Reason is simple, you have a 2.75" woofer vs. a 5" trying to compensate. Treble is comparable on both speakers, both are pleasant. A5's have better bass but that goes back to the woofer sizes. This is not to say that the A2's are a bad sounding speaker (they're still very good), I just preferred the A5's
One thing I will agree with is if you're just using them for yourself to listen to music, A2's are a good choice. If you have friends over and need something louder, A5's would be the better choice.
Other options that weren't in that thread I linked are the Emotiva airmotiv 5's (449) or if you can stretch your budget to $800, KEF is releasing some '
computer speakers' that are going to catch a good buzz in the trades.