THIS IS WHY WE AGREE TO DISAGREE!!!!
If loop B doesn't equate to processing 0's and 1's any faster than loop A they are both the same, in my books.
When you are talking close to ambient temps, 3-5c isn't going to make failure on an overclock. My point all along has been all these loops, regardless of size and color, will achieve pretty much the same overclocking potential. If one wants the most out of a CPU they shouldn't even look at watercooling and go straight the peltier or phase.
If loop B is able to use the extra 3-5C to be able to sustain an overclock, then it is better. Having an extra 5C of headroom is a substantial amount. For example, being able to supply 1.45V core to a CPU and having it load at 45C instead of 50C means you'll be able to bump up the Vcore again and push the multiplier/fsb a bit more. That extra 5C just bought you more headroom allowing one to push your CPU harder than what you would have felt comfortable with with a weaker/inferior loop.
For example, one would keep pushing his OC until he would hit his personal temp ceiling of 55C. If the loop A w/ the same e6600 would hit the 55C load ceiling at 1.45 vcore to get 3.6 Ghz and the loop B can use those extra 5C to push it a bit higher to 1.475 vcore to achieve 3.7Ghz before it hit the 55C ceiling, then loop B is better.
I'm not sure what most of us see that you can't.