Filtering is kind of hard to describe. If it's what I'm thinking of, it makes the ground/walls look clearer at a distance. For instance, if you stand still facing forwards, with no filtering, the ground a few metres away will look like a blurry mess. With filtering on, it will be clear and you'll be able to see detail in it.
I'm not sure how powerful the 320m is compared to the PS3, but console hardware is old, and if you have a decent computer you will be able to achieve better graphics, as consoles usually run at a low resolution, low-ish frame rate and low-medium graphics. But graphics don't matter, so get it on whatever you enjoy the most (and remember you get a free PC/Mac copy with the PS3 version).