One of the interesting aspects is the whole 'loot' system that they have in place. From what I've seen so far it seems to be cosmetic items as well as weapons with slightly different stats than the 'standard' model you unlock at whatever level. (example being an 'alternative' model has +1 extra mobility but -1 range or something like that). Now if you receive a weapon from a level you haven't reached it you can't use the weapon 'standard' or 'modified' BUT you can trash that item for XP that adds to your level overall. I just did that there now with a weapon I couldn't use (for level 32 and I'm 12) and it gave me some xp which helped take me from level 11 to 12.