Those of you saying that you open tighter vs. better players,

I agree, somewhat. But I think more than how good they are needs to be looked at.

A 35/25 who is a 1 PTBB/100 winner.

A 19/16 who is a 3 PTBB/100 winner.

Clearly the second is the better player (he makes more money, on average, per hand). However, would you not agree that opening a wider range vs. opponent 2 and a tighter range vs. opponent 1 is correct?

How would you know what their actual win rates are?

I agree Xaston. I open my SB very liberally against tight players. They almost never adjust to that properly.

Even if the 35/25 guy isn't that great I still will play pretty tight against him, especially if he 3-bets a lot. I don't like playing big pots OOP even if the guy is a marginal loser. If he's a total donk but raises a lot, then I might start limp-calling in the SB to get into smaller pots with him (although I rarely get into this situation).