It depends on the games and DirectX. If you play nothing but older games (more than 9 months), then the 30.82s should be fine, but newer games will need newer drivers. There are a lot of game-specific fixes (not just "optimizations" for benchmarks

) in the drivers. The newest dets also include DX9 support, and though no game currently uses DX9's advanced features (unless you consider 3DMark03 a "game"), the game may still require DX9 to be installed.
So, use what works best for the games you play, and when you have a problem with a game, try newer drivers. I personally use the latest detonators, updating quarterly at least.