I helped my friend install this on his 8800gt, the tape on the RAM sinks was COMPLETELY pointless... should have just left it off, save us all some time and grief of removing it. And the heatpipes blocked the RAM sinks on his card as well. Still the cooler is crazy good--friend's 8800gt runs 55c on load.
Put some faster fans on this thing and it would be killer, but still only two of the heatpipes touch the core.
My Powercolor 3870 runs folding@home all day and never breaks 64c with a way smaller zerotherm cooler. I like the zerotherm that came with my card over this thing though. The fact that you can only get two heatpipes over the core could save xigmatek a lot of money, if they would just merget the HDT with zerotherm's design--I think that would be sweet.
^^As for this being good for a 4870 stock..... not sure dude, it would be good for any card pretty much, but it's sorta overkill for a lot of people, it's really big man... I'd check out zerotherms.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814131095 <--- this is my card dude, i'd suggest getting the zerotherm attached to this one.