I think it depends to a large degree on what stakes you play at. Personally, I play the fishy stakes (25NL) so I generally don't slowplay a set. I usually bet the flopped set reasonably hard to maximize profit if there is no draw (2/3 to full pot), and bet it really hard (overbet pot to AI) if there is a draw on the board. It upsets me when my sets lose. I bet it hard when there is no obvious draw since that kinda is the point of playing pocket pairs. Most ops at the microlimits are simply not aware or not expecting a hit set so if they're gonna call down with their mid/top/2 pair, they'll do it anyways whether you're slowplaying or not.