[Harv72b]

There are a few things you need to take into account, in addition to the pot odds being laid out to you & the strength of your draws. First of all, there's no guaranteeing that you'll win anything at all if you runner runner your way to a winning flush--in a 7-way pot, five players checked to a moderately aggressive guy in late position, who then bet & was flat called in four (so far) places. It's more likely than normal that the turn will get checked through (especially if it's a card which really helps you, like the 3 or 5 of spades or an ace), and when that happens then it becomes less likely that you'll win big if you do end up with the best hand. And even if you do improve on the turn and CO bets again, there's no guarantee that anyone else will call that bet.

So, basically, your implied odds suck, but your reverse implied odds also suck because the pot size means you'll often be forced to check/call to showdown if you turn your ace. With the size of the pot, this is at best a breakeven situation equity-wise, which means that peeling will only add variance to your game without affecting your longterm win rate either way. Or in short, just fold & wait for the next hand.