I've been goofing around in some of the more popular free to play games on steam. My thoughts;
WarFace - A pretty crappy game overall, but perhaps I expected far to much. Aside from the disappointingly crude and rudimentary graphics, the same can be said for the actual gameplay and the ways in which the combat mechanics function. Its just no good. I put 5 hours into the game and that will probably be it.
Heroes & Generals - I share about the same opinion as WarFace. I know its in Beta, but jesus christ... talk about rough around the edges. I do have a bit of light hearted fun tinkering around, as the actual combat is pretty easy. I actually can get somewhat into the game for an hour or so at a time. Really, for me the two most disappointing aspects of this game is the artwork (specifically environments) and the rigid and glitchy game mechanics.
Ghost Recon Phantoms - Despite Steam saying I magically played this game for 53 hours (not true, wtf) I played for a good 2-3 hours and am likely to never play it again. Reasons being the same as WarFace...