[MarkGritter]

Patting is almost always the right option here.

(1) Can you win the pot more often by drawing than by patting?

You will more often make a worse hand at showdown by drawing than by patting. Your odds are at least 3:2 against making an equal or better hand. Probably worse. If there were no future betting, then patting would be a clear favorite.

The third opponent will probably not have smooth-called with a better pat hand often enough to be worth worrying about. If he habitually slowplays (but doesn't snow) then just fold when he shows up pat after this line.

(2) Will you have to put in a lot of bets with your 87 when you don't know where you stand?

Possibly. This is the area of most concern. Don't get trapped for multiple bets if both players wake up. But don't be too eager to break, either. If you need to improve your hand to win on the last draw, you are only about 6.6:1 to win (probably less in a 3-way pot.) That means if you are already ahead just 15% of the time it may be better to call a raise and re-evaluate on the river.

This is partially opponent-dependent, but it is better to work on improving your reads and late-round play than make an inferior draw here. The pot is already large and you should try to win it. Even if you have little chance of knocking out a player when you bet the next round, it is even lower if you draw here!

(3) Will you pass up the opportunity to win a lot of bets by making a stronger hand?

Unlikely. Some of your 5's and 6's likely reside in the other players' hands. In order to win a big pot both you and your opponent would have to hit well--- and it might well be you paying off with #2! Meanwhile you may miss collecting your share of two more big bets on the next round.