Even though the NVIDIA GeForce 8800 Ultra was released recently, its price premium is certainly too high to be affordable for everybody. Based on the award-winning GeForce 8800 GTX, Zotac created a new product which offers higher performance than the plain GTX - about 10% - yet is not super expensive. Unlike the EVGA ACS³ 8800 GTX, the cooler has not been modified for improved cooling. This has very little effect though it seems, the card is still quiet and not getting too hot.
Zotac includes a warranty with their overclocked card, so you don't have to be scared of losing your warranty when overclocking, like you would on a normal 8800 GTX. In my opinion the extra $xx are a good investment for people who want a hassle free solution that works well, so that they won't have to invest their time overclocking and losing their warranty from doing so. On the other hand, if you are more experienced you could just get a normal GeForce 8800 GTX and overclock it yourself to reach a similar performance level.