If anyone's still interested...
I've built systems using both the Antec Aria and the Aspire X-QPack, and they both have pros and cons. The Antec is clearly a more robust case, but you only have one 5 1/4" external drive bay, as opposed to two on the Aspire. The Antec comes with an integral memory card reader, although there's a 3 1/2" external bay on the Aspire where you could install one for about $15, which is roughly the price difference between the two. The Aspire also has a 420watt supply, as opposed to the Antec's 300watt unit.
You also only have the exhaust fan from the power supply on the Aria, and while it's a 120mm unit, it's not as quiet as you'd expect it to be. Not that it's particularly loud, but it's not silent. The Aspire case, with a proper CPU HS/F combo, is nearly silent and has two exhausts - 1 120mm unit, and the 80 in the power supply.
Speaking of HS/F combos, in the Antec case the CPU ends up under the vertically mounted power supply. This seriously limits what kind of heatsink you can install in the Antec. You're going to be stuck with smaller HS/F combos, which are usually noisier than the bigger units. It also makes it an iffy case to put Intel CPUs in, since effective processor cooling is difficult to do and you have a somewhat lightweight power supply. You don't have either of those problems with the Aspire unit. The last Aspire case I used got an A8N-VM/CSM mobo with an Athlon 64 3700+ (San Diego) cooled by one of those new <a href="http://www.pro-clockers.com/article.php?id=155">Zalman CNPS8000</a> heatsink/fan combos. Pretty spiffy.