Pros: Cheap, effective, and easy to install (follow the directions, almost). See other thoughts for more.
Cons: None. Will probably buy 3 more. This is a keeper.
Other Thoughts: If you follow the directions, and/or have put on an Intel HSF before, this is a 5 minute install. DO NOT try to push the pins in and twist them. Push them in and they will lock automatically. Someone below explains this better. P5E WS Pro (also an awesome product), Q6600 (quad core, 2.4GHz), 8GB Corsair RAM. FSB at 425, stock voltages. Was 2.9GHz, now 3.4Ghz and seems to have more headroom. I'm in the US, so I'll state *F. Ambient temp is about 80*F due to 5 machines in 1 room. In Phoenix. In July. Idle temp was 102. Now 92 with the higher overclock. Core temps idling was around 129-131. Now 112-115. Running Prime95 (100% CPU) core temps were around 185. Now 160-163. I'm typing this while Prime95 is running, and you'd never know it. I'm really impressed. And thanks NewEgg for good service and fast shipping.