Is it worth buying an FX6600 ?

My FX 5200 is still causing troubles so I decided to buy a 6600. The FX 6600 seems to be a good card with an excellent price/quality ratio according to the tests I read few months ago. First, is that worth buying a 6600 ? Then, my PC is a 2.09 Ghz CPU (Athlon XP 2600+), 512 MB RAM. Could I exploit all the possibilities of such a card with my configuration ? See what I mean ? Is my CPU powerful enough to make a 6600 working really fine or not ? If not, any other good card I should buy instead ? :)