it will make a difference. The colors will be more vibrant and it will be a little bit clearer. Get the $20-25 cable for the PS3. It works on both. Just make sure you buy the one that is actually made by Sony. Don't buy anything else unless you are either looking for less than stellar performance or your looking for problems. I bought this cable and it really does make a difference. It's more than worth quarter the price of a new game.
The difference between standard connection and 480i is still breath taking at moments.