As it turns out, I was the one in the small blind with 7532, and caught a 6 on the first draw. I was reasonably happy with my hand until my opponent put in the fourth bet after the first draw. At that point, I thought I had to seriously consider the possibility that I was beaten. I thought that a sane, solid player could only make that bet with a fairly narrow range of hands, probably all of them 7s. If he has a 7, I'm probably behind. The only question was whether he was a solid, sane player or not, and I had no information-- an online 5-10 game is about where you start running into people who know how to play.
I decided that check-call was probably a reasonable play at that point. There was no chance in hell I was folding, but I didn't feel like pouring a lot more money in. If he has a worse hand I don't want him to break and draw, and if he has a better hand I want to lose the minimum.
In discussing this with someone, I got called a nit. He said that he wouldn't play 76532 any differently from 75432. That felt pretty maniacal to me-- it seems that there's a pretty big difference between sevens in TD. (In single draw, sure. I'll pour a lot of money in with any 7.)
In retrospect, it seems reasonable that I might have bet the second draw, and call down if I get raised. I think the check call is not wildly conservative, though.