If the Acer has an advantage in performance, its design offers only a little bit more than that of the eMachines system. The cases are more or less equally bland, although we prefer the eMachines because it has no irritating gimmicks like the hard-to-open, sliding plastic door that covers the Aspire M5100's media card reader. Each system also offers a reasonable degree of upgrading, with a handful of free expansion slots, including a 16x PCI-Express slot. They're also both equally limited to only mainstream 3D card upgrades, because each uses a 300-watt power supply that would likely choke if you matched it to a more substantial 3D card.