Summary: With that said, if it's an option for your build, there are some supported motherboards that can run non-ECC memory if you look around.
Pros: Excellent CPU for the price. We're using ours in a box hosting several game servers. Very quick, very cool, and low power draw.
Cons: This isn't necessarily an issue with the CPU, but as other reviewers have mentioned, most motherboards that support this CPU require ECC unbufferred/unregistered memory. It's difficult to even find individual DIMMs over 4gb, and when you do, they're extremely expensive.
Pros: Four cores, eight threads, high clock speed, and 80W max! Totally blows away my older dual dual-core Opteron 2220 system in all benchmarks except floating-point. However, this new Xeon pulls off the feat at about ¼ the power consumption. Less heat = fewer fans = less noise = cooler room = happier customer.
Cons: My five-year old Opterons still still beat this Xeon in my floating-point benchmark...barely - and that was two physical CPUs.