After finally upgrading to a 2500K, it was apparent very quickly that I needed to upgrade the heatsink, as the stock one was unable to even run at stock settings under full load. After looking around, I found a review on HardOCP of this heatsink and the immense value it provides for the money. The install is a bit laborious, but once installed, it runs fantastic. It's dead silent and cools great. Everything I wanted. =)
Also, the currently shipping models have the "new" brackets, so they work out of the box with ASRock and Asus motherboards.
Note: If you pick up this heatsink, be sure to get a long phillips head screwdriver in order to secure the heatsink. If you look, there's a hole at the top of the heatsink. This is used to access one of the two screws needed to secure it.