depends on what you expect out of your headphones in terms of audio signature.
the hd598 is a good all-rounder with a neutral sound signature, more laid back smooth sound and decently wide soundstage. if you are not quite sure what you would like, this one goes right down the middle so most people would like the sound signature. the only people it will not please are those looking for excessive amounts of bass.
cans like the ad700x and ad900x are more focused on treble and mids with rather poor bass response. they are more detailed with much better positional audio and soundstaging. there is a definite advantage to gaming (fps games) with them due to being able to hear footsteps much easier (due to almost no bass). when i mean no bass...