I have the BX2's plus centre and surrounds and I've been very pleased with them. They were right for my budget at the time, and I wanted wall mounted surrounds.
If I was looking now however, I too would be interested in the aero's but if you are looking to get a centre and surrounds at some point then they will cost you more than the BX range.
On paper the Aero's appear to have the edge, but can you get a demo?