Bought a previous generation one last year to run as a NAS for work, and I hadn't had to even reboot it in months. So when it came time to buy one for home office, this was a logical choice.
The dual-core processor won't win any speed contests, but is more than adequate to run VMware ESXI 5.0. I have it running a real-time firewall/malware gateway software (eSoft's virtual Instagate), and it still has plenty of power left over. Windows Home Server will be going on this thing next!
Pros: Built-in RAID 0,1 support Extra screws and allen wrench included in door Easy hard drive installation and removal Compact, half-height mini tower Super quiet. Put in some green hard drives and you won't even know the machine is there. Runs VMware ESXi like a champ. No issues with installation.
Cons: Wish it had RAID 5 Compactness made it a little difficult to add extra Gigabit Ethernet card. The process requires unfastening multiple connectors and thumb screws to be able to slide out the motherboard.