I bought the 2 fan version for my Lenovo IdeaPad Y470.
Unfortunately, at best it only cools the Y470 by at most 1C (maybe).
I don't think it's a problem with the cooler itself since the CM allows you to place the fans where the vents are underneath the laptop. The problem is the limited number and size of vents the Y470 has; there are only 3 vents:
Vent #1 - This has an intake fan which cools the laptop. Placing the CM cooler fan does not improve cooling since using a fan to push more air into another intake fan does work. Maybe if the CM fan was pushing an excessive amount of air at 10,000RPM a little extra air might be pushed through the intake fan, but that's doubtful.
Vent #2 - Roughly 2" x 1",but even with the CM fan directly...