I think XBL cheats a little when it matches you up to players, i tend to find the same people with consistent connections over and over again while PSN i get a wide variety of people ranging from extremely bad to extremely good connections.
so xbl prioritizing people with good connections so that you fight them more than those with bad connections is “cheating?”. i would define that as actually having a good search algorythm as opposed to simply matching you up with the first person regardless of connection ping.
360 is much more polsihed online than PSN. Experience more drops and overall connection issues on PSN.
Trust me ive played enough on both to know ;).
SF4 killed my 360 because i over played it. i have to get a PS3. lol