If go by this click here the X1950 PRO (at 11.30 Frames)scores better than the ATI Radeon HD4550 (at 9.00 Frames)running Crysis v1.21 and does in most other game tests (put a tick next to each one and click compere at the bottom of the page).
Thanks everyone. I just swapped the X1950 for the HD4550 and both the graphics and the gaming graphics scores on my Windows experience index were lower. 5.9 & 5.8 with the X1950 and 5.1 & 5.2 for the HD4550.
So there you have it. It would appear that for my computers configuration at least the X1950 is the better choice.
Oh well, time to swap it over again!
I suppose I could always flog the HD4550 on eBay!!