I had a danger den maze 2-2c in my 2nd watercooling system, and found that it had a hole just under the lid that leaked. I emailed them about it and they sent me an identical block... with the SAME DEFECT! I coated it in silicone and wrapped it in electrical tape to prevent it from leaking.
A few weeks later I came home to the smell of fried processor. Something tripped the power cord for my pump, and my peltiers heated up the waterblock enough to melt the solder holding the top of the block on. The solder would've dripped onto my video card hadn't i wrapped the block in electrical tape. I emailed dangerden and they responded asking for more information about what happened. I wrote a page long description of exactly what happened, and they NEVER responded. I sent many more emails [all very civil], and none of them were answered. I took my grief to my favorite tech forums, and found a lot of other people had been screwed by dangerden in one form or another.
In short, buy
Swiftech. Their products and customer service are far superior to any other company I've dealt with, especially dangerden.
note: don't let this horror story daunt you, it's more a reason to not use peltiers than to not watercool; although my overheat-protection software should've shut the computer off in time, it either wasn't turned on or wasn't working... and I paid for it with a motherboard, processor, network card and 3 sticks of memory.