Catalyst. You get what you pay for, don't expect this to run every game coming down the pike on ultra.
This card is just over a year old now, I've owned mine for about 8 months and it has exceeded my expectations considerably. I initially bought it for a mid-level gaming rig in conjunction with the new line of Sandy Bridges that had been recently released. I did my research when trying to find the most decently priced graphics card that would be able to play most of the games out there today at reasonable FPS and graphical quality. This card did all of that and more. It overclocks like a dream over its marginal factory overclock. Reading a lot of internet reviews of the overclocking potential, I seem to have managed an overclock above and beyond what most people can expect (975Mhz/1175Mhz). This card can essentially give you the performance of the $30 more expensive 6870 for a few mouse clicks. I managed to do this with a slightly higher performance, 550W PSU, than is required for an unoverclocked card.
As for the downside of this card, I can only say that lies not in the card itself, but in the Catalyst software. While it provides the overclocking and voltage tweaking software, I found myself using Sapphires' TRIXX utility to handle the overclocking on the card. The Catalyst software is slow and clunky at times, in addition to the the clocks on the card not sticking after restarts sometimes. I also found the Sapphire TRIXX windows gadget to be the only one that worked with this card. Additionally, the wide range of max overclocks for this card, while largely dependent on the other components of the system, should be taken into account if you plan on doing any sort of overclocking with it.
In conclusion I believe this is one of the best cards you can buy for the price, though with the new generation of GPUs just around the corner it may not be for much longer.