If you want a good reason why you shouldn't slow play a set here is a good one.

Ultimate Bet No-Limit Hold'em, $.25 BB (10 handed)

Hero ($14.85)
UTG+2 ($6.75)
MP1 ($21.40)
MP2 ($4.50)
MP3 ($9.90)
CO ($44.65)
Button ($13.65)
SB ($28.45)
BB ($23)
UTG ($17.80)

Preflop: Hero is UTG+1 with , .
Hero calls $0.25, 2 folds, MP2 calls $0.25, MP3 calls $0.25, CO calls $0.25, 2 folds, BB checks.

Flop: ($1.35) , , (6 players)
BB checks, Hero bets $0.5, MP2 folds, MP3 calls $0.50, CO folds, BB folds.

Turn: ($2.35) (3 players)
Hero bets $1, MP3 calls $1.

River: ($4.35) (3 players)
Hero bets $2, MP3 calls $2.

Final Pot: $8.35

Results in white below:
UTG doesn't show.
Hero has 7h 9h (four of a kind, nines).
MP3 has Jh Jc (full house, jacks full of nines).
Outcome: Hero wins $8.35.

If he had raised me at anytime I probably would have folded. But instead he let me stay in and catch runner, runner to beat him.

I don't think I played this very well, at least on the turn and the river. The bet on the flop was just sort of a feeler bet - an "ok, lets see were we are at", type of bet.
When the turn brought another 9 I still didn't feel real confident about it so I just doubled my bet. I supposed I could have check raised the river or potted it to try to make more but I was afraid he would check down the pot if I checked and fold to a pot sized bet. So I chose to just double my bet again and hoped he would raise me or at least call.

hehe....1 out of 990 on the flop for quads. I think he can slow-play that one

Of course you had the gutshot draw as well...but still

I dont subsribe at all to the dont slowplay a set every theory. Sometimes you have to take the risk the turn card is going to miss the draws in order to get someone whole stack. The trick is to know when your slowplay killed your hand, like when the flush card hits and there is lots of action before you. One of the spots I have gotten a lot better is the ability to not chase, and to let go of the monster.

Limping suited one-gappers from UTG+1 and leading with Middle-Pair-No-Kicker and a 1/3 pot-bet into 5 players on a super-draw-friendly board might not be optimal play either

Stoneburg - you are, of course, correct. I had no business being in that hand and played it poorly. I was behind before the flop, behind after the flop, behind on the turn and won the hand. It was pure luck, of course. Yet my opponent allowed me to get there under my own terms.

Yes, Kenny and Rhound, slow playing a set is a very common and profitable play. Nothing wrong with it at all. But the irony here is that, by playing so passively, my opponent played himself right out of the hand.

As far as the 1/3 pot bet - that is a play I have used quite successfully at the low limits that I play. A nice quiet way to win some money off the calling stations when I have less than a monster hand and no one seems to have hit the flop. I'm sure that, now that I am stepping up in stakes, I will run into players who will run me off the pot - but when they don't I sometimes get lucky, or often the second pair is good.