I'm generally playing pp from any position to no raise and calling one bet with them preflop. If it's two to go before it gets to me and I don't have reads I'll generally fold them but if the original raiser is of the any ace will do variety I may call. On the flop if I miss I'll call one bet with a PP if the board isn't coordinated enough that my set would give someone else a straight or flush. If I'm HU with someone whose range of raising hands is wider than AA-QQ I may call him down if there are no high cards on the board.