[AaronBrown]

I agree with the previous posters, and would emphasize CurryLover's point that this is a question of strategy, not ethics.

If anything, the ethics favor betting. Checking down to maximize the chance of eliminating a player is a faint whiff of collusion. Only an oversensitive purist would call it unethical, it has become an accepted tournament tactic. But the most ethical thing you can do in poker is to play every hand for your maximum personal advantage, rather than considering joint advantage with another player.