Yeah, I can see why. That's the worst kind of flop to see when you've got Kings (well...actually it's better than seeing one with one ace, since it means you're that much less likely to run into it). Glad it worked out.

On the set hand, I agree with 'rilla. The thing is, there is a straight draw on the board. In NL, as soon as you have the best hand, you need to start dropping the hammer on boards with draws to make it a mistake for the player you're against to call. Straight draw = 8 outs = 31.5% to come in by river and about 18% to come in on the turn. So you want to raise it at least enough that with 18% odds + implied odds, a call is bad. 2/3 the pot is generally good here, but at micro levels, might go ahead and make it pot-sized.

Another difference from limit is the inability to check/call to a showdown cheaply. If someone is betting like they made a hand that's better than yours, they probably did (unless you've seen similar behavior from them on a bluff before).