I received the FX5200 today; the good news is that it works, the bad news is that I thought it had a 128 bit memory bus, but it's only 64, just like the NVS280 and the 9200. The scores on all 3 benchmarks were within the noise to identical to the 9200 once I went from the 56.64 (the oldest official driver for the NVS280) to the 43.45. You could likely edit or force install that driver on the NVS280 and get the same result.

I force installed the 43.45 driver with the NVS 280 and, as predicted, the result was nearly identical to the 5200.