I'm surprised by that...
NorthQ's coolers are exact clones of the Asetek coolers* and Asetek's 120mm model is ordinary compared to the H50 as I recall.
Corsair did a few substantial mods to theirs, they didn't base it in entirely on the Asetek version.
*NorthQ themselves explained this to me, they even admitted they're sometimes a minor revision or two behind the Asetek version.
IIRC, they use a different RAD, upgraded pump and better contact plate. Can't remember where I read that but is on the web somewhere.
Its a good review but the Corsair H50 is 2 degrees cooler on the load temp
Corsair:
http://www.ocia.net/reviews/corsairh50/page4.shtml
CoolIT:
http://www.ocia.net/reviews/cooliteco/page3.shtml
I've been considering puttnig a watercooling system onto my Q6600 CPU, as the box tempertaure maxes out at 41°C when I've been playing Fallout3 for a while (just dropped an ATI 5870 in there, which has upset the airflow inside compared to the old GTS8800), and i figure this would be a good way to reduce temps rather then drilling more holes in my case for more fans
from what's being siad, the Corsair seems to have more user reviews saying it's top notch... but is it £15 better?
The CoolIT is on offer this week at £52
The corsiar is £15 better than the coolit on everything but amd so you will see the difference, tbh though, the megahalem with push/pull performs very close to the h50