Well he did say he's not a serious gamer, that means that FPS isn't his top priority. Maybe good DVD hardware, or superior image quality is what he's looking for with a little spunk to play those games once in a while. And for what he's looking for I think a Radeon DDR would suit him best. But then again the MX is no lagger, certainly something to consider, expecially if you run linux, or want something drastically cheaper.
Either way it's a steal when considering price/performance, but I think the Radeon DDR will last you just a bit longer, maybe not as long as the warranty is provided(5 years), but will certainly chug that system along for some time to come.