EK's biggest problem is quality control, always has been. Stuff slips through the cracks with that company, especially their GPU blocks. Their CPU blocks tend to be good, their fittings aren't bad (use those myself sometime), but their GPU blocks are crap, a Heatkiller GPU block on ANY GPU will stomp a hole in the face of the comparable EK block, performance wise.
EKs only real positive is availability. It certainly is NOT quality, and me and about 1,000,000 other water coolers will attest to that.