Graphics card question, please help?

Is there much difference between an Asus ATI Radeon 9550 128Mb agp and a Gigabyte ATI Radeon 9600 Pro 128Mb agp? (need to replace the 9550, as it died. This computer will soon go to my 6yr old daughter, although I am in need of a boat anchor, but I'm not sure how well it would sink!).