I also don't know how much XP we get; but I do know you get more from winning that losing (obviously) but you do also get xp when you lose. If you attack a lower level you also get less xp for a win.

Yeah, I kind of stopped attacking for a while because only a few were around my level and I didn't want to attack lower levels; I also think they may have changed the drop rate of chests, the big advantage I had was that I got some really good drops early on when no one else was getting weapons I had like 5 of them lol. You officially have about 50% of my total losses lol