Summary: Great for workstations and multi-threaded computing, but not so great for 'less-cores' applications (gaming and whatnot)
Pros: I have 2 of these installed on a ASUS KGPE-D16 server board as a workstation for architectural modeling/rendering. I have to say, with 32GB of RAM, these CPU are blazing fast when rendering. Just to give you an idea, with my set up, all default un-modded settings/drivers, I scored 12.27pts on Cin...
Cons: Clock speeds are pretty low...I tried running 3Dmark pro on ultra settings and I can barely get over 2200 even with a GTX 580 overclocked GPU. Well it's a 12-core server CPU, what do you expect?
Pros: I bought this a year ago to make a FEA simulation machine. Average uptime of 60%. If I'm not running simulations, I donate the computational time via BOINC. I run Windows 7. It's a 12-core desktop.
Pros: I am using 2 of these in a dedicated server for building Android software. It's doing a great job of it, I can build an entire phone in 13 minutes (Android, linux kernel, and a bunch of customizations on top of that). Lots of RAM channels means fast access.
Cons: They get hot when used, you start a build and the dual fans start spinning up loud! (Not the CPU's fault). Low clock speed means single-threaded tasks are slower than on comparable processors. Not compatible with the cheap DDR3 1333 GSKILL memory I bought (would only run 10660 , so I am going wit...
Summary: While some of the fastest Intel processors have faster individual cores, and are a better choice for fewer faster threads, for applications that run dozens or more threads, these CPUs are great.
Pros: I run two production database servers which both have 4 of these CPUs and they scale almost linearly. The memory bandwidth is unbelievable with 1333MHz memory.
Pros: I put two of these in a workstation. Hits the sweet spot for performance/watt and gives me a fantastic tool for HPC R&D. Also, as a developer these processors make short work of large builds. I plan on upgrading to the socket compatible Bulldozer processors next year.
Cons: So far so good on Windows 7 64-bit. I'm using VirtualBox to run several guest OSes as well. The procesors run cool and stable.
Summary: It really depends on your application. Where more-cores can be utilized, and the clock-speed is not AS important, go with these. Another note, if you are thinking of going with some 6-core Intel processors, is that there is a 2.3GHZ version, that still costs less than intel's higher clock 6-core,...
Pros: This processor absolutely smokes. With an entry price of $759.99 (at the time of this writing), it puts you around 22.8GHZ of power. Have two of these in a Supermicro box doing call processing, works great.
Cons: None so far. The only thing is that it has the same amount of cache as the 6-core, as the 12 core is really just two-6 cores.