
As
bluemax pretty much said Rad9000 is NOT DX9, it is DX8.1. The ONLY card at the mo with DX9 is Rad9700, but DX9 is very pointless for at least 12 months IMHO anyway.

Rad9000 is simply a cut down Rad8500, in nearly ALL games pas present and future the Rad8500LE will beat the Rad9000pro. ATI have done with the Rad9000 what nVidia did with their GF4MX, released a slower largely inferior product with a newer naming than the previous better card, GF3 and Rad8500 respectively. The Rad8500 gives GF3 perf while the Rad9000pro gives GF4MX460 perf but it also offers DX8.1, Rad9000pro is much better than any GF4MX BUT not better than Rad8500. With prices being so small between the Rad8500 and Rad9000 cards it makes NO SENSE at all for the vast majority of people to go for a Rad9000.

Here's a few good links about Rad9000pro (about 20% faster than Rad9000):
Tech Report
AnAndTech
Firing Squad
HardOCP
Doh!, if the 4200 cards are that cheap get them, they are killer cards and if so closely priced definitely the card to go for!
PS. Rad9000pro also uses DDR so it actually runs at 275/550 to GF4TI4200's 250/500, but clock speeds aren't in any way telling of perf and 4200 64MB cards o/c to about 300/600 (faster than 4400's 275/550), the 4200-128MB cards are still the better oiption, but if you can get a bargain for a 64MB version it definitely still rocks!