Warlocks have received new spell effects; all the other classes received new effects in Legion. Male orcs are now able to toggle between the initial hunched posture and standing upright by using a barbershop, but the other races are not able to toggle between two postures. There are new druid forms for the allied races, i.e. a Zandalari troll forms are all dinosaur-based, while the Kul Tiran humans take forms made of wood and bone as their teachings come from the Drust people who populated the land before them rather than the Cenarion Circle.
Mag'har orc - "For untold generations, the orc clans of Draenor battled one another in endless war. But when Gul'dan offered them the blood of his demonic masters, the disparate tribes of Mag'har—the orcish word for "uncorrupted"—refused the dark bargain and banded together to drive out the Burning Legion. United under the leadership of Grommash Hellscream, the Mag'har pledged to one day repay Azeroth's heroes for aiding their cause. As war against the Alliance intensifies, the Horde must call upon the might of the Mag'har to seize victory."
Level 65 unlocks Greater Invisibility. This can be used to instantly escape combat with any enemy, or reduce the damage of big hits by 90%. Keep in mind, when using Greater Invisibility, you will drop combat, and lots of enemies will start evading and healing back to full Health, so do not use this on low Health enemies if you would survive the hit.
To give you some perspective I leveled both a LF Ret Paladin and BE Rogue (so one started from level 20 and the other from level 1). I focused on getting the achievements I was missing for the Loremaster, so not the most efficient route by any means. I was using full enchanted heirlooms (minus the ring) and the WoW-Pro addon though, as well as having War Mode turned on all the way.
Despite the fact that World of Warcraft still relies on the old 14-year-old game engine, the game can cause some frame rate drops even on newer hardware equipment. So we've decided to devote a lot of time and space to answer such questions like: How to set up the graphical options? What should I do to make sure that WoW runs smoothly? WoW's hardware requirements have evolved over the years due to graphical improvements, so find out if your computer can handle the highest graphics settings of the game.