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.
A "stat squish" and "item squish" was implemented to lower the numbers used in the game, e.g. a legendary item previously with a level of 1000 reduced to 265. Unique class-specific buffs are added back, i.e. mages' Arcane Brilliance and priests' Mark of Fortitude. Titanforging—a random event that raises the initial item level of an item gained via drops or rewards—is still in the game; however, if the item is one of those affected by the Heart of Azeroth, then that item cannot be titanforged.
Before anyone asks - yes there are archived copies of old addon versions both on our github repository and on several of the addon sites we use, and these will continue to be available after Cataclysm comes out, so you'll be able to get those old files if you really want them. I'm not going to bother making these more easily accessible unless you give me a very good reason. "I'm on a private server and I need them since we didn't upgrade to Cataclysm" is a BAD reason - and it's illegal.
Warmode is one of the real stand-out features of Battle for Azeroth, even if it is a somewhat controversial one. Warmode tries to revolutionize world PvP like the game has never seen. By switching on Warmode, you enter a new version of your server with only other people looking to fight out in the world. The result is a more volatile world where fights can break out at any time, and groups from to go fight the opposing faction.
DoTs: Assuming that the mob is going to live for certain periods of time, it is worth it to place DoTs up. If the mob lives for at least five seconds, cast Pain. If it lives at least seven seconds, cast VT. The ideal time to cast DoTs is when it would be replacing Flay, but you can substitute Blast if the mob will live longer. Make sure to cast Bolt on cd though!
When an allied race has been unlocked for a player, new characters from that race will start at level 20. If a player levels an Allied race from 20 to level 110 without using character boosts, they will be rewarded with a unique "Heritage Armor" for transmogrification that reflects the unique lore behind the race but is limited for use to that race. Doing the quests to unlock the allied races will also unlock the races' unique mounts for use by the characters of their faction. The void elves, Lightforged draenei, Highmountain tauren, and Nightborne, as races tied to the storyline for Legion, were made available with the preorder on January 30, 2018. The Dark Iron dwarves and the Mag'har orcs are made available upon completing the "War Campaign" in Kul Tiras and Zandalar and reaching Exalted with one faction's War Campaign reputation; the Kul Tiran humans and Zandalari will be made available later in the expansion. Game director Ion Hazzikostas also indicated that additional Allied Races may be available in the future.
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.