The only downsides are the fact that the fan can get a bit noisy when set to above 40% mark, something still needs to remedied. But if the majority of people don't play with the fan speeds, there is no concern. While there are not any true DirectX 11 games out yet to allow the HD 5800 series to take advantage of the technology, it means that we are still playing a waiting game. One more thing is the availability of the 40nm 5800 series - the same problem that ATI had with the HD 4770. Currently, there is only one 5800 series card in stock at the online retailer Newegg: no 5870 and only one 5850 SKU. It seems like ATI is missing the golden goose on this launch. Otherwise, this card is awesome!

http://www.overclockersclub.com/reviews/xfx5850/