Overall, Quag has absolutely no offensive pressure, gives too many things free switch-ins, is an unreliable stealth rock setter and look: 252 Atk Reckless Mienshao Hi Jump Kick vs. 252 HP / 252+ Def Quagsire: 199-235 (50.5 - 59.64%) -- 84.77% chance to 2HKO it gets easily 2 hit by a scarfed mienshao even with maxed out physical defense. And it also can't take anything at all on the special side: 252+ SpA Porygon2 Tri Attack vs. 252 HP / 4 SpD Quagsire: 175-207 (44.41 - 52.53%) If you want to use Quagsire to stop moxie sweepers, that moveslot is better used by something that counters that moxie sweeper in the first place. Let's say your opponent has a LO Honchkrow. True, quag ignores its boosts, but becuase Quag is so frail, you essentially have to give Honch a free kill before sending it in becuase it gets 2HKO'd by Brave Bird. I agree it may seem on the same level as something like Swampert on paper, but Swampert boasts much better defenses, the ability to hit much harder, a greater variety of viable sets and roar, which gets rid of boosters anyway. In a typical UU battle, quagsire will only very rarely be given a reason to come in, and most of those reasons have u-turn or potential coverage moves to take it down.