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.
The idea of the expansion came up after the heroes of Azeroth dealt with so much external threats like the Burning Legion. In their own words, "so when we talk about what's the biggest threat in this world, is it the titan or is it the dwarf paladin that put a hammer in that titan's head"? As such, the enemy (at least during the early parts of the scenario) will be the opposite faction, a "vast army of world-destroying forces".
Void elf - "Many have sought to harness the corruptive magic of the Void. Most who tried have fallen into madness. Determined to use this power for the good of Azeroth, Alleria Windrunner is the first mortal to succeed at defying the shadow's whispers. Coming to the aid of a group of her kin who nearly gave in to the darkness, Alleria has vowed to train these Void Elves to control the shadows within them and pledge their newfound powers to the Alliance."
A central problem of long-running MMOs like WoW is that the player's numbers have to continuously get bigger and bigger in order for the player to feel more powerful. When the original game released back in 2004, player health pools topped out in the thousands of hit points. Today, everyone is running around with absolutely massive numbers on their stat sheets, many of which have climbed into the millions. Players can deal out an equally massive amount of damage and it's gotten to the point where there are so many large numbers flashing across the screen during combat that it can be hard to keep track of exactly how well you are performing.
Anyway both got to 110 at around 50h played. I messed up with my Pal by going to Legion once I hit 100 instead of finishing treasures and bonuses in WoD. All in all, if I picked the best zones and was only trying to level as fast as I could, I would probably could have done it in roughly 40h. Note that it would have a been A LOT faster with a Monk as both Ret and Rogues don't really have a decent AoE until 40+ (45 for Ret and 63 for Rogue I believe). The daily also helps a lot. I know that leveling my Monk before the pre-patch was insanely fast. Might be slower with the changes to FoF, however.
There’s a lot of #content in the new expansion. It’s mostly locked behind a variety of gates, some of which players can’t even control. Warfronts are the best example. You might assume joining a Warfront is a simple matter of opening the group finder. Wrong! Warfronts are only accessible for a week at a time. It’s not precisely clear how often that week will come around (it’s based both on a time gate and on the opposing faction gathering resources) but, as of right now, it looks likely to be available just one week out of every four.
Elixirs serve the same purpose as Flasks, but the buff expires if you die. You'll only use these between 1-70, generally speaking, until you can start buying Flasks which persist through death. Try not to die, and carry extras just in case. If you can't find an Elixir with the stat you want, look under scrolls, since they count as battle or guardian buffs as well.
Meanwhile, on the island continents introduced in the Battle for Azeroth expansion, players level 110 and above who have unlocked world quests can participate in Faction Assaults. These special events, alternating between Alliance and Horde territory, will give each faction a chance to band together to defend their territory or invade their enemy’s via a series of world quests. The prize? Survival! Also faction, gear and gold. Maybe even some pride.
The downside is that War Mode will make you vulnerable to other players, which means you might be killed more often. Whether it’s worthwhile will depend on the zones you’re visiting and how active the other faction is on your server cluster. Heavily populated realms usually mean more players on both sides, and more conflict, but on quieter realms, you may rarely run across an enemy.