The problem is that the 13" MBP is over twice as fast in many benchmarks, but people think "if they had just put a better fan/heatsink on the air" they would be the same speed.
I wonder how much faster the 13" Pro would be if they did a similar setup.
In this[0] iFixit teardown (of last year's 13-inch, they don't have one for this year yet, but I assume the inside layout hasn't changed much), the cooling setup is a lot more traditional with a heatpipe from the CPU to the fan. I don't think it'd get a lot of benefit from the watercooling that LTT did (at least, without Apple's power profile taking over and throttling).
The only reason I can think of that Apple set up the MacBook Air like that was because it was supposed to be fanless and at the last second they couldn't figure out a way to eek out performance, so they added a fan where it would fit. That doesn't sound much like Apple's engineering though, so I don't know why they did it.
