Bit Tech published their first Watercooling Radiator shootout, in which they look at the HWLabs Black Ice GTX and TFC X-Changer series' of radiators.
"Both the Black Ice GTX and the TFC X-Changer series of radiators are well designed, but it's clear that there's definitely a difference in performance for the price increase. Feser's performance starts off with a nice and cool two degree difference at idle on the 120mm radiator, and though the idle difference shrinks as the sizes increase as we'd expect, the temperature differences at load continues to increase.
Looking at either extreme, we have cost vs. performance issues. The TFC X-Changer is almost 50 percent more expensive than the Black Ice at the 120mm level, but we start out two degrees cooler at idle. Granted, most people should not attempt to cool an 8800GTX and a Q66600 CPU on just a 120mm radiator, but it quickly sorts the wheat from the chaff - the TFC X-Changer wins hands down. At the moment it looks like you'll be paying quite heavily for that privilege - however, if you're looking at cooling a lot in a small space and you've already bought into watercooling, it'll be worth the investment without question. "