I'd say it should perform reasonably well but as always make sure you get a good price cos the current mac laptops offer significant value for money in terms of raw power and features.
I personally have the 667 DVI tibook and its still going strong 4yrs later. I use it for your typical consumer stuff(itunes,web email etc) along with Photoshop and Painter. It may be slow now compared to the new kids on the block but it handles old enough games reasonably well too. It can run Medal of Honour, Halo and Call of Duty. While the setting are all on medium, the games are still very playable and enjoyable.