Free to Play
Weapon upgrades are done via in-game credits which are earned through playing.
Visual appearance is changed via micro transactions. Hence everyone tends to look the same :p
The most things i don't like in the free game is, the big difference in power from paying and none paying customers but if you say updates are done in ingame credits then it might be fairer
Yeah weapon upgrades are gained from in-game credits which are earned through playing. The look of your character is the bit that the charge real money for.