Actually i got the damage territoy of 4.4% that i am upgrading right now - not kowing how much it will increase
with every upgrade, the power of an artifact doubles (4.4% to 8.8%)
If you have everything you "want" from the level in regards of Powers + Artifacts, all that's left to get from completing it is AP and the Achievement of clearing the map. If you don't care for these, quitting loses you nothing.
AP is something you always need....