It's not pay to win, it's veteran power creep. Simply speaking, the RPG-ish mechanics of unlocks and upgrades in freemium models favor older players. It doesn't matter if the player in question spent $500 on the game or not; he's just better by virtue of playing the game for longer, because that means he has access to more unlocks, more upgrades, or at the very least - more options(these can be an advantage too). There's plenty of examples of this already in game. Veterans get 25% more health, more accurate weapons, bigger magazines for vehicles, borderline hacks like NS/NV, etc. That's why in freemium models it's very important to upgrade sideways, not up. More options, more niches - but not new upgrades that will push the veterans further and further ahead of the new players. And now, implants.
I like the PS2 model against veteran power creep by putting very clear delineators on how much you can creep in any given area. PS2's model means that as a new player, you are at a disadvantage against someone who is not due to cert differences. However, fast-forward at most 10,000 certs (yes, a lot) and someone with 10,000 and someone with 1,000,000 certs is going to be the same power level within the chosen class/weapon/etc. The guy with a million has other class/weapon/whatever's he can use, but the less experienced person is still at the peak of their game if they chose to specialise. Furthermore, the amount of boost you get isn't nearly as hugely significant as it is in other games. The +25% health is less of a factor when the TTKs are so low and the amount of boost vs. amount of damage is relatively small. In WoW (for exmaple), two level 5 guys going PvP with a level 80 guy have no chance. In PS2, two BR 5 guys going PvP with a BR 80 have every chance - with the main deciding factor not being the cert advantage but the sheer number of hours spent playing by the BR 80 and thus being actually better at the game. And now implants.
One of the "antidotes" for the normal freemium experience is tied to the fact that PS2 is, for the most part, a skill-based game. Whether a person has ground through hours of play to purchase everything with Certs; or is a little whale who buys everything off of the bat with Station Cash, in the end, all of those numbers and stats rely on the person to pull them together with their ability to move, shoot, and then hide or run away under fire. I think, more than any system-ingrained quirk, that requirement of human skill is what's saving this game from the label of "pay to win" sticking. Unfortunately, this new "implant" idea is cutting off that skill at the knees and saying, "hey, want to pay Migby for some cheat codes?"
