(I've actually submitted the same message on the Koolance forum but after submitting I got a message my post needs to be approved by a moderator first and I'm suspecting they will not post it.)
I've always had an Evercool WC-202 watercooler in my system. It's a complete system including pump/resevoir/fan/radiator (combined in one) unit, CPU cooler, VGA cooler and seperate case radiator/fan. The entire package retailed for less than $100. It was whisper-quiet and cooled my CPU down to 90F under normal load. I was pretty happy with the system but during a holiday in the States (about 3-4 years ago), I stumbled upon the RP-980BK. This was only the pump/reservoir and for the price of this unit alone I could buy two complete Evercool systems. But I figured because it was Koolance, and quite an expensive unit (compared to the $90 or so of the complete Evercool system), I could expect something even quieter and something that would cool even better.
When I returned home from my holiday, I replaced the pump/reservoir unit of the Evercool with the Koolance unit. They use pretty much the same tubing size. When I first switched on the system, one of the things that became apparent immediately, was that this thing was noisy. I mean, really, really noisy. In fact, with the pump speed at it's highest it was unbearable noisy! I had to turn down the pump speed all the way to 1 and even then it would still be much louder than any fan in my system. Not what I expected at all.
The second thing that surprised me, was that it cooled a full 15F less than the cheap Evercool system. My CPU temp was now 105F under normal load. Increasing the pump speed to 10 made a difference of only a few degrees. Not wanting to go through the trouble of replacing it with the old Evercool, I kept the unit in my system.
After a few weeks, I noticed coolant coming out of my computer case. Fortunately I had made an airduct just below the unit (because the Evercool also had a fan/radiator in the pump/reservoir unit) and that directed the coolant outside of the case. If that duct wouldn't be there, it would have undoubtedly leaked all over the motherboard and other plug-in boards. I was lucky. I opened up the RP-980BK and noticed the pump had cracked. After only a few weeks of use at its lowest pump speed. Needless to say I wasn't all too happy with it. I emailed Koolance and I had to send the defective unit back to them (from Europe!) before they would replace it under warranty. I put my old Evercool system back in and sent the Koolance back. When I received the replacement unit, I actually just threw the box unopened in my closet. The Evercool was doing a much better job than the Koolance unit so I left it at that.
3 years(!) went by before the pump of the Evercool broke down. This was 6 months ago. It was actually my own fault because I had used some Teflon tape on one of the fittings and small pieces of it had came loose and jammed the pump. By now, the Evercool system was no longer sold but I still had the replacement RP-980BK. I unpacked it and replaced the broken Evercool unit with the Koolance unit. Again this thing made a lot of noise. Not so bad as the first unit but still I had to run the pump at its lowest settings so the noise wouldn't drive me crazy.
You see, the biggest reason I want a watercooled system is not because I want better cooling, but I want silent cooling. I work in an environment that's very quiet and any noise coming from my PC is very distracting (and annoying).
Anyway, 6 months pass and the pump of the Koolance calls it quits. This second unit lasted only 6 months - again only with running the pump at its lowest speed. But even though I only used it for 6 months, it was a long time out of warranty.
I ordered a replacement pump from the Koolance website on Oct 11. On Oct 12, the status page said it was "ready for Mail Pickup". It stayed like that for days at end until I finally send them an email on the 17th asking them what was taking them so long to ship the item. I got no answer but all of a sudden, the same day I received a "Click-N-Ship" notification from USPS. Apparantly Koolance had forgotten to actually ship it. On the 18th, I sent another email to Customer Support asking why it took them so long to ship it. Again, I received no answer whatsoever.
Anyway, today I received the unit. 9 days shipping time really isn't all that bad from the United States. When replacing the old reservoir/pump with the new one, I noticed the tubing is a little bit too short. Not all that much but still about 1/5". The only way I could make it fit is by not sliding the tubing all the way over the fitting. If this has any ill effect I don't know (I don't suspect so).
I filled the system and switched on my PC. This third unit is even noisier than the previous two! Even at its lowest setting it makes a lot of noise and as I'm typing this message, I'm finding I'm getting terribly annoyed by it. It's even noisier than the stock CPU fan I had in my system while waiting for the replacement pump. I've actually recorded it with my cell phone at a distance of about 5 inch. I start with speed 1, then increase pump speed to 10. Now the beeps you here when I increase the speed gives you something to compare the noise with (the beeps are pretty loud).