I replaced the AIW 9800Pro with the AIW X800XT with good results. I use dual Dell 2000FP displays at 1600x1200. One is driven using DVI the other with VGA from the card. The AIW 9800Pro would drive the 2 displays but I had to use the Cat. 4.5 drivers and a $50 DVI splitter cable. The AIW X800XT is using the Cat. 6.2 drivers. Initial tests show a step change (almost 3X) in the 3D Mark score (no overclocking). Part due to the newer drivers and part to the card.
There are other threads and web sites that have reviewed the performance of this card and several other cards (Toms...) and based on their test I expected about a factor of 2 improvement over the 9800Pro (8 pipes vs 16?).
A friend bought the 7800EV(?) and his scores were indeed much better than mine with the X800XT but he paid about $80 more than I and the AIW X800XT has the TV tuner and FM tuner.
My system is built using ABIT IC7-G, P4 3EGHz Prescott core, 2GB Corsair PC3200 CAS2.5 Value Select, Fatal1ty X-Fi, Logitech G7...