I don't get it. The stock cooler performs far better than all the alt coolers, yet it's not recommended? Sure, it's louder, but ramp up the fan speed on the alt coolers to that of the stock and I'm sure you'd have similar noise levels.

yeah, the stock cooler rocks. Forget about sound levels, if you want to have the card more than 1 year, you should stick with the stock cooling solution.

Usually high-quality after-market GPU coolers manage to do both - keep your card cooler *and* be quieter. That's two reasons to buy them, either to keep your machine quieter, or to keep it cooler (or both). As you can see, the Scythe and Arctic Cooling heatsinks are both quieter and more efficient for the GPU indeed, but it seems this time the designers overlooked a very important factor (VRM cooling). What is really surprising is that no other reviews I've read of say the Arctic Cooling unit mentioned this.

Now I'm a bit stumped, I was planning to get a 4870 1GB and either the AC unit or the Thermalright T-Rad2, though I have a hunch the latter would have the same VRM cooling problem...

I got fitted AC Accelero S1 rev2 together with two 120mm MAGMA UCMA12 fans, with red stock heatplate fitted and I got 37 degrees VRM at idle and 70 degrees at 95% GPU Load and noise level is way lover than 35% stock fan so if you dont mind having a little messy set up and got quite a lot place inside and dont mind that all takes around 3.5 slot then I would suggest fitting it that way. It is way more enjoyable than the stock cooling.

Artur