Let me give you my Koolance Experience.
I bought a Koolance RP-452x2 version 1.2 dual bay res last march.
the thing leaked from the very beginning.
I live within driving distance of the koolance corp office and took it to them.
it ended up being that the cylinder that slides over the pump was not creating a good enough seal with the o-ring.
they showed me this and I thought. ok my bad. then the guy crossthreaded my pump mount on the bay during reassembly.
he cracked the black acetyl and when I got it home it leaked again.
They have terrible QC and the engineering staff took 3 years to figure out that they needed to redeisgn the product to mount the pumps with a plate and screws instead of cylinder sleeves.
All the new designed pump mounts have the extra plate with 4 metal supports because enough people at OCN *****ed and got them to reengineer the designs of all the pump mounts.
I went with a ek pump mount instead and I will NEVER buy another Koolance product again.
here is what I replaced it with... much better quality and koolance basically copied ek's design to fix all there pumps

Frozencpu.com
Part # Product Description Qty Price Total
ex-pmp-97 EK 5.25" Mountable D5 Dual Loop Top - Black Acetal - Laing D5 / Swiftech MCP650/655 (EK-D5 Dual TOP 2-Loop G1/4 - Black Acetal) 1 $89.95 $89.95
ex-res-338 EK Link 50/60 Reservoir Adapter (EK-Multioption RES X2 - LINK50/60 1xG1/4) 2 $15.99 $31.98
ex-res-342 EK-Multioption RES X2 - Top w/ Thread 2 $8.95 $17.90
ex-res-349 EK-Multioption RES X2 - Tube 60/100mm 2 $18.95 $37.90
Item Total: $177.73
Shipping: $75.24
Tax: $0.00
Subtotal: $252.97
Discounts: -$8.89
Grand Total: $244.0
I have 2X GTX 580's in SLI on one loop with a 360mm rad and a i7 2600k @ 5ghz on the other loop on a 240 rad.