The stock performance of the Pure Black X58 is impressive when you put it up against a board from mainboard stalwarts Asus. It even manages a slight win in the gaming benchmark.
Unfortunately it's when you start trying to push the board to its limits that Asus' greater experience in the industry shows. The overclocking performance of the Sapphire board lags a fair way behind the Asus P6X58D-E, itself a much cheaper board.
The sad fact is though that if you're looking at the more budget end of the X58 chipset and CPU combo then you're going to get soundly beaten by an equivalently-priced Sandy Bridge rig.
In its stock 3.5GHz state the i7 2600K with a P67 board outstrips the i7 920/X58 combo on all fronts.