I bought two G80 waterblock from them. It killed two XFX xxx 8800 gtx before I realized the waterblock couldn't properly touch the GPU chip. According to Kooland I had to "grind" the waterblock 1 or 2 mmms...
Hopefully XFX accepted to RMA my cards.
Recently I bought a few quick disconnect from them, it's nickel plated. So far it works amazing. You can can disconnect your waterblock put another one in your loop without the need to redo everything.
My point is, no matter what company you try sometime the quality is good sometime it's bad. Of course there is a trend but not always.
I used to think also that thermaltake is bad but their toughpower PSU work like a charm.
So check professionnal review and take biase opinion with a pinch of salt (can I say that in english?