YOu didn't mention (didn't notice?) that it also has a faster processor.
I think 100 pounds to get double memory, 33% more hard disk and a faster processor and a DVD writer as opposed to just only being able to write CDs is well worth it. Only you can answer whether those things are useful to you though.
RE: Games I wouldn't imagine those sports games would be particularly taxing but maybe they are these days. Look at the minimum/recommended requirements on the websites for the games and try and make sure you have at least the minimum.