Slow play? It depends...
In my home poker room, I have a rep on the 1/2 NL tables as being very aggressive. My raises get no respect. There is usually no reason to slow play. On the 2/5 table, I'm less aggressive because there are several players way better than me.
Last time I was in Vegas, I was getting beat up by players way more aggressive than me. I was on a very deep stacked 1/3 table. I had to fold post flop even after I had big raised pre-flop, because even my big pre-flop re-raises were getting 4 or 5 callers. Very often I was having to decide if my over pair or top-top was worthy of calling off my entire stack. My confidence was low.
So I went in my shell, played super tight, didn't reveal my strong hands with a raise. After an early position raiser opened for 7X, he got 5 callers including myself with QQ in the cut off. I didn't want to blast the pot and win $100, I wanted to win a big pot. I flopped top set with no open ended straight draw or 4 flush. I watched a $100 bet, call, and re-raise to $450 in front of me and only called, with one caller behind, making the pot ~$1600
Obviously they were suspicious of my call, but 3 of us saw the turn which did make straight and flush draws a possibility and might have completed a gut shot straight. There was a $500 bet, a fold and then I re-raised all in. He only needed another $450 to make the call, but he tanked and folded. I made $1600+ profit on the hand which made me profitable on the day. The $500 bettor packed up his chips and left an unhappy camper. He must have had nothing but air, thinking he could get me to fold anything.
Was my slow play risky? Yep. I think it was worth it and I was willing to give up the QQ post flop if I didn't connect.