You can’t play Xbox or PS players with PC.
Competition is rather scarce compared to XBL and PSN, I’m sure.
It comes down to preference. I prefer to play on PC and it’s too bad most of the players seem to be on console but that’s how it is.
You can download character model skins for the PC version, if that’s of any interest.
Competition isn’t so bad, though. There’s always a game to find in either ranked or player matches, and if you’re new, there will be plenty of championship games waiting too. The higher grade you get in championship mode, the player base gets smaller because most players don’t spend the time in championship mode.
You start with G3 grade. I’m G1 now and the instant I ranked up from G2, it felt like I was in a wasteland. Never had a problem finding a G2 match. The good thing with the PC version is that you can host a game and watch a movie at the same time.