i like the idea of progression true challenge, it allow a progression while getting out of its comfort zone and it ditch the K/D ratio XP that plague every mode but slayer. the thing is, some challenge are just over the top, i have to kill 10 player with a plasma sword, use a fuel rod i have never seen in the game, and kill someone with the reflector.
i get the idea of reward true effort. but there is a balance.
it remind me a handgun in BF4. you have to open a stupid gate in sunken dragon(1 time per match), and i spent 30-40 match swapping server just to be the first to open this gate.
when the challenge kill the objectif of the game. just change the challenge.
im sure a ballance can be find. kill 10 with plasma weapon seems a good start.
otherwise i love the game.