Honestly, the 5800 Ultra is a very nice card. The vanilla 5800 is similar, however, not as likely to overclock- nor does it have the badness factor (open to interpretation...)
The 5800 Ultra is extremely rare. Most were sold as reference cards that were actually hand-built for nVidia. This includes hand-picked cores and extremely fast Samsung DDR2 rated for 1100Mhz. People love to sneer at the cooling solution, which is noisy- however it is also very effective and quite a marvel to look at.
If you carefully look at the fill-rate of these cards you will see that the core is able to keep-pace with the newer 'refreshed' 59xx series. However, the advantage goes to the original nV30 simply based on clockspeed- most reference 5800U's will exceed 550 Mhz core clock with the factory cooling solution (some even higher). The 128 bit memory bus is really only a disadvantage at very high resolutions with AA.
...at any rate, enjoy the card. Too bad you couldn't have gotten an Ultra. I thought PNY still had some for sale on E-Bay?
Here is the little-known nVidia 5800 web page, check-out the 3-D 'board tour' listed at the lower left