I have a 5600 which I assume is similar, and it is quite good, but I think you would be better off spending about 100 quid or so, as it would buy you a card more able to cope with the very demanding games that are the norm these days. (HL2, Doom3, Halo2 eventually, stuff like that)
in one of my pc's.It will play all the latest games including Far Cry,Doom 3,half Life 2 etc at a decent resolution so yes it will be fine. Add to this the fact that this card was over £100 just 2 months ago then it's a bargain.Go for it,I can recommend it.
I would recommend my own card. It doesn't seem to have any problems with any of my newest games that I have chucked at it. While they are not the most demanding out there anymore, I think that with the current high performance, it would run alot of the newer games out now pretty well.
Its a Leadtek 128Mb FX5900 TDH XT. It was 7th in the PCA tables until the new cards all came out. I bought it for £180 in Febuary, but I think I saw it for around £100 online somewhere.