I recently got the Swiftech MCW 462 U and running my rig with it now.
Epox 8KHA+
Athlon XP 1800+
Right now its at full load with 33 C, running Seti. CPU is O/Ced to 1.7 ghz with 1.85 V Core. Running Seti without O/C and default voltage temps dont go above 30 C. Ambient Temperature is 22 C.
I am using the Perma Cool radiator (you can find a pic at crazypc.com) and the Eheim 1048 pump. Tubing setup was ahh interesting considering one part of the pump is 1/2 ID, waterblock 1/4 ID, rad 3/8 ID, and the other part of the pump 3/8 ID.
Radiator is being cooled by a YS-Tech 120 X 38 fan, which is suppose to put out 130 CFM. Its running on a volt modded line though (overclockers.com has an article on how to mod the wiring), so its less airflow (and quieter).
Temp readings arent accurate since they are from MBM and not a temp probe.
I know this isnt a professional review or anything but its just supposed to give you an idea
Only gripe i have about this block is the quick connect fitings for the tubing. If you dont push hard enough its gonna leak, big time.
So far so good.