Wow! That was a hell of a lot to read.
While I am not very active here, I thought I would put in my 2cents worth. I have several WC setups and just posted a reivew at
Gruntville of the
Alphacool Cape Kit like the one at the top of that page.
I have also built/reviewied a "typical American" setup with the
PolarFLO SF block, Eheim 1250, BIX2, 1/2" tubing, etc. In addition, I have had on this setup the MCW-5002 and Whitewater.
Now, I admit my testing is not nearly as scientific as what the gang here does. However, I do think that it is at least accurate enough to give you an good idea of how this stuff performs in the real world. And since I have experience with both types of setups, I can sum up the differences pretty good, depending upon your situation. So here goes....
If you are an Exteme Overclocker....
.... then brute force is what you are looking for. Every degree counts. So go with a big 1/2"ID system and the PolarFLO/RBX/WW/MCW6000 block of your choice. Put the biggest pump you can in there and a radiator from a Kenworth and go to town D:
For the casual overclocker and hardcore gamer (we all know most games don't like the extreme overclocks)....
... then you have a choice to make. The top German kits perform much better then "adequate" and will keep your system nice and cool and look good doing it. However, since only the Innovatek and Asetek kits seem to be easily available in the US, it might be cheaper to go the "big" route. It will come down to costs and aesthetics.
For the quite PC person....
... you have a similar choice as the casual overclocker, but would lean more towards the German-style kits 'cause they are quieter.
I happen to really like the German kits for water cooling a smaller case, like an Antec P160 or even a SFF system. Heck, look at the Y2K Bug that
Mashie dd. You would never fit a 1/2" system in that thing.
I guess the bottom line is that each person much prioritize what they are looking for in a water cooling kit. Think of performance, noise, ease of use, and aestehtics. How you rate each one will determine which approach works for you.