Now that the VR subforum has caught up with Mega Pinsir, it's time for my "I told you" post (previous posts: http://www.smogon.com/forums/thread...v2-check-post-530.3502428/page-6#post-5321219 and http://www.smogon.com/forums/thread...v2-check-post-530.3502428/page-8#post-5327881).
There are strong arguments about moving Mega Pinsir to A+ both in this thread and in the VR one, and at this point it's hard to deny that the metagame has greatly shifted against it, with pokemon such as Zapdos being very common and Defog becoming an increasingly less safe method for removing hazards.
Speaking of Defog, a common scenario is using it late-game so you can safely set-up with Mega Pinsir and attempt to sweep, only to be met with a +2 Defiant Thundurus who craps all over Pinsir and possibly the rest of your team. This means you should be using Rapid Spin over Defog, but with that you'll have to deal with Aegislash, who is a pain in the ass for every spinner (yes, even Excadrill) not named Mega Blastoise, which you obviously can't use in the same team.
As powerful as Mega Pinsir is, its issues with entry hazards and lack of versatility compared to the other S-rank pokemon mean it should be dropped to A+.
'its issue with entry hazards'
Oh, then should Mega Charizard drop as well? Having a weakness to entry hazards doesn't make you automatically suck. And yes, it has a weakness to Stealth Rock, but you're forgetting it is also immune to Spikes and Sticky Web, which is a positive. It lacks versatility? Could you elaborate, it only needs three moves to be deadly, as do many other things. I agree it has a bit of a problem setting up, but after, its 'checks' do not check it anymore, for instance:
+2 252 Atk Aerilate Mega Pinsir Return vs. 252 HP / 252+ Def Zapdos: 198-233 (51.5 - 60.6%) -- guaranteed 2HKO after Stealth Rock and Leftovers recovery
It can no longer switch into Mega Pinsir and:
0 SpA Zapdos Thunderbolt vs. 0 HP / 4 SpD Mega Pinsir: 254-302 (93.7 - 111.4%) -- 62.5% chance to OHKO
It does not secure the OHKO on full health Pinsir. And if you haven't set up, then you get hit twice by Return (maybe even 3 if you it survives the Thunderbolt), but then you're left for anything else to kill you, see:
25.7 - 30.4% + 25.7 - 30.4% + 25% (SR) = 76.4 - 85, if Zapdos has already switched into Stealth Rock once, then Mega Pinsir overwhelms it, and if Thunderbolt does not OHKO it, then Mega Pinsir wins again, although it is weak too. But I will give it to you that Pinsir will not always be at 100% and have SR off the field. But you go and say that Defog is unsafe thanks to Defiant, of course, but not every team runs Defiant and no good player will use Defog on an opponent with Defiant Pokemon. And Excadrill is only pained when Aegislash has its Air Balloon in tact, but not every single one runs it and it gets popped after one hit, so you can't say that Excadrill is not a good matchup against Aegislash. Mega Pinsir is a very powerful Pokemon, and I'd like to see you come up with one Pokemon that can avoid being either 2HKOed or OHKOed by +2 Mega Pinsir, I'll get the obvious ones out of the way:
+2 252 Atk Aerilate Mega Pinsir Return vs. 252 HP / 232+ Def Skarmory: 142-168 (42.5 - 50.2%) -- 39.5% chance to 2HKO after Stealth Rock and Leftovers recovery
+2 252 Atk Aerilate Mega Pinsir Return vs. 252 HP / 252+ Def Zapdos: 198-233 (51.5 - 60.6%) -- guaranteed 2HKO after Stealth Rock
+2 252 Atk Mega Pinsir Earthquake vs. 252 HP / 0 Def Mega Tyranitar: 350-412 (86.6 - 101.9%) -- 93.8% chance to OHKO after Stealth Rock
+1 252 Atk Aerilate Mega Pinsir Return vs. 252 HP / 0 Def Landorus-T: 406-478 (106.2 - 125.1%) -- guaranteed OHKO
+2 252 Atk Aerilate Mega Pinsir Return vs. 252 HP / 252+ Def Hippowdon: 318-375 (75.7 - 89.2%) -- 56.3% chance to OHKO after Stealth Rock and 1 layer of Spikes
+2 252 Atk Aerilate Mega Pinsir Return vs. 252 HP / 184+ Def Gliscor: 321-378 (90.6 - 106.7%) -- guaranteed OHKO after Stealth Rock
+2 252 Atk Mega Pinsir Earthquake vs. 252 HP / 0+ Def Filter Mega Aggron: 162-192 (47 - 55.8%) -- guaranteed 2HKO after Stealth Rock
+2 252 Atk Aerilate Mega Pinsir Return vs. 252 HP / 0 Def Rotom-W: 233-275 (76.6 - 90.4%) -- 25% chance to OHKO after Stealth Rock
+2 252 Atk Aerilate Mega Pinsir Return vs. 252 HP / 252+ Def Rotom-W: 169-200 (55.5 - 65.7%) -- guaranteed 2HKO after Stealth Rock and Leftovers recovery
Now I know Calcs are not everything, but they still prove a huge point. And yes, I am aware that setting up Swords Dance can be difficult, but if you manage to set it up, then it is hard to stop without a Skarmory, which does not fit on every single team. And even without SD it is still scary as hell. I like running Sub > Quick Attack, and although it seems weird, it shields me from Burns and allows me room to set up. But sacrificing QA is pretty huge. In my opinion, Mega Pinsir is a perfectly great S-Rank threat, as it has a huge blend of power, priority, and even bulk (65/120/90 is not too shabby). And although it doesn't have the best typing in the world, its weaknesses can be overcomed, and that is what S-Rank is, Pokemon who can cause serious havoc with some team support, but not much. Really, what Mega Pinsir needs is Defog and that's pretty much it... I fail to see anything but S-Rank for Mega Pinsir.