I would have done so, but i got my card when the 5870's first came out so they were all standard reference coolers.
if id have known they were noisy in the first place i would have waited.
Just surprised that you can't even buy a better and quieter cooler than the stock ones.
Prolimatech, £45, I'm running full load overclocked/overvolted 5850 at 36C load, with 2x92mm fans at silent. The heatsink actually works better with 92mm fans than 120's that most reviews use as the deadspot on the 120mm fan(the bit in the middle) is much bigger on a 120mm and a lot of the airflow is not going through the heatsink while the deadspot covers large portions of the sink.
I've not actually tested the VRM temps with the included heatsink, they aren't great in reviews, but thats ONLY in furmark. With the Thermalright heatsink on the VRM's, i'm getting 70C in furmark, but only 45C load in games, furmark just gives temps you will NEVER EVER see in any game ever, its a completely useless tool because even for stability, what might make furmark crash will never crash in games.
Its expensive, but has so many mounting options it "should" fit the next gen cards, and the next gen after that, which if it does, would mean you've ended up paying about £15 for a cooler for each of 3 cards, which is cheaper than buying a Vapour x type model. Realistically the Vapour X is better than stock, but not by much, its still got high temps isn't particularly quiet and you normally wait months before 3rd party versions are out.
With the Prolimatech they are promising to bring out new mounts very quickly after launch, IF it doesn't already fit the pretty large array of mounting options it already has.
This has been my main gripe with 3rd party coolers, and non reference heatsink versions of cards, they very very very rarely come out within 3 months of launch. The Prolimatech isn't strictly speaking a 5870 cooler, but it still arrived 6 months after the card launched. The 5870/5970 Arctic cooling sinks still aren't available AFAIK. Last gen the 4870x2 Arctic cooling solution wasn't out till 7-8 months after the card was.
Waterblocks do tend to come out quite quickly for these cards, but all full cover blocks are wasted cash in terms of moving to a new card in the future and very few people want to pay extra for a 2nd hard card with a waterblock so little chance of resale.
Even worse than all of that is, the Prolimatech costs so much because its made in small numbers, if it was the default heatsink, AMD would have less failures, almost complete silence and 99% of people that buy the cards anyway only ever use one expansion slot, the vast majority of people could fit two triple slot coolers in for crossfire as a LOT of AMD boards these days, 790/890fx boards anyway, have great spacing for 3/4pci-e slots.
Blower fans and exhausting heatsinks are UTTER CRAP, 70-80C load down to 36C load with a better and quieter cooler thats only marginally bigger.
If only they did a quadfire version like the reference cards with exhausting double slot louder heatsinks in small numbers, and the "normal" version with a huge ass sink in it for the 99% of sales where the space under their GPU is completely wasted and better cooling and silence is prefered.