I support Hippowdon for A+. Although it does often need to be a full health to tackle what it's supposed to, which is its greatest flaw, its defining trait is that it tailored to beat specific threats ranging from Band Terrakion to Charizard-Y. The fact that it can check both Pinsir and Aegislash with the same spread is also pretty impressive. He's also pretty easy to fit on balanced teams due to his access to Stealth Rock. The rise of Sand Rush Excadrill benefits him doubly, because not only does he provide sand for bulkier Sand teams which prefer him to Tyranitar, he also deals with opposing sand teams pretty well, especially if it's a Sand Force variant (which is usually chosen if Sand Rush conflicts with another Pokemon on the team like Dragonite or Venusaur), although he can't really beat Excadrill if it carries an Air Balloon instead of a Life Orb.
As for Heatran, I think what stops it from being A+ worthy to me is its 4MSS. It wants Rocks, Lava Plume, Toxic/WoW, Roar/Taunt, Earth Power, possibly Stone Edge/Ancientpower and Protect (this last one is actually really important since it gives you a way to get health back as well as rack up status damage, stall out weather and scout for choice-locked Pokemon). This means it can't really deal with everything it wants to with the same set. However, it still has a great typing and solid bulk with really important resistances, as well as a few good sets besides the standard specially defensive one, including Scarf, Specs and offensive SR setter with Air Balloon, so it may well be worth moving to A+.