iClassic is neither play or pay to win, since everyone is equipped with the same weapons and no matter how much you play or pay that won't change. Everyone will always be on an equal playing field.
Nothing needs to be said about iEra, pay2win all the way.
iZone is play to win, there are tons of noob accounts with high kills/spar ratios, and you can do very well without spending any gralats; and due to the combat = $$ system you can move up with weapons just through PvP and PvE.
Delteria (iDelteria if its been released yet?) is play2win.
And I have never tried playing Ol West but I have it DL'd and just saw that it was a reskin of iEra, so I'd assume it is also pay2win.