Not much traffic on this forum these days, so time for a little case study which illustrates the importance of knowing equity of your hand against various other hands.
I haven't played a lot lately (read: about 1k hands in October), but on UB I'm facing more and more hyperlags and the following example may give you some ideas of how knowing some numbers may help in battling them.

Disclaimer: I'm writing this mostly to sharpen my own thinking about spots like these, and to get a bit of discussion going. I'm not stating matters with any kind of authority, just to test them against your critical thoughts. Oh, and everything I know about PLO I learned from adam of course.

Assume that your opponent is a hyperaggressive but thinking player who views you as reasonable. He relies on stealing tons of medium sized pots; most opponents are afraid to play for stacks with weakish hands and when they finally play back at him he will simply give up, shove it in with any kind of draw (even if odds aren't there he has to protect his game plan) or call, depending on likelyhood of opponent bluffing.

It should be clear that, especially at a shorthanded game, waiting until you flop a set or a monster draw is not going to be profitable. This may work in full ring or against maniacs, but not against good lags. In fact, this is exactly what they hope you'll do. (They also hope you start playing back lightly out of frustration.)

So, here's the kind of play you can not only make a stand with, but also frustrate their overall strategy with.

Say you have [9d][7s][6d], and are in the CO. Lag in EP raises pot. Too many people flat call here. This is a mistake because of two reasons: first, it entices others to enter the pot, and now you may face problems if you flop a small flush draw since you may be crushed by a higher flush draw. HU against the lag you are happy with any kind of flush draw, so the hand plays a lot better HU. (Also, if you're in a multiway pot you have bad relative position since people in the blinds will look to CR the lag.) Second, you wish to gain some control over the hand and use position. The lag has 4 cards, you have coordinated cards, and especially if you haven't been reraising a lot you want to convey strength and have some folding equity on dry flops.

Now the lag calls of course, and you get a flop of [9h][5d]. You have a gutshot and middle pair, and two backdoor flush draws (and a crappy backdoor straight draw). Without thinking about it, what do you think is your equity if villain has a hand like [Kd][Th][4c]? If the lag leads into you should you fold? Call? Shove? And why?

Let's look at our equity. On this particular board against this particular hand, we're 51% to win. From the lag's perspective he has top pair on a dry board, you're unlikely to have a set, so he will likely lead into you. Remember, he knows you have next to nothing most of the time. Surely, you reraised him, and you may have AA, but even then he has some folding equity and if you call/raise, he has some outs.
Surely, there are other hands he may have (in a way, this is the worst possible hand he can have with which he may play for stacks) but it is unlikely he has us in horrible shape. The cases in which we're crushed are far outweighed by the cases in which he's betting with nothing. Moreover, he's also quite likely to play hands like 3678 for stacks against which you're in great shape (up to 80% or so, depending on backdoor flush draws).

So you're shoving over his lead, and you're doing so because
1) You're not often very much behind, and have equity against his calling range.
2) You're showing him that if he's in a pot with you you're not going to be bullied
3) If you were to call then on a blank turn he's likely to fire a huge bet again, and you are likely to make a mistake. Normally you wish to make the best use of your position, but against this type of player things change a bit.
4) You may get him to fold similar weakish hands and draws. (Since the pot is large already this is a fine outcome of course!)

Most of us think of middle pair and weak draws as garbage hands which cannot stand any heat. To recognize that in certain circumstances such a hand can not only be a mathematical favorite but also should be played hard and fast is an important aspect of playing shorthanded against very aggressive players.

Equally important is recognizing how our equity would go down if we didn't have the backdoor flush draws: it drops to about 43%. Give the opponent a backdoor flush draw and things get worse for you. And think twice before shoving if another flush draw is present: if your opponent has it, you're in bad shape (around 27-30%).

Conclusion: if you give up on flops like these then you shouldn't be in this game. It goes against the nature and training of most of us to be highly reluctant to shove flops like these but unusual circumstances dictate unusual measures. Oh, and if you're playing in a game like this, then have a 50buyin roll at least for comfort, and don't be surprised about 5buyin swings within half an hour of play.