These stat priorities help to get a rough idea of what gear to go for, but the most important thing to get as soon as possible is your stat weights. Stat weights help you zero in on which stat is the most effective at increasing your healing. However, healers have no grand simulator, as there are a lot more variables that can affect your overall performance than there are for DPS specs. In light of that, healers use fight analysis tools like WoWAnalyzer and the Teachings of the Red Crane spreadsheet that takes logs from WarcraftLogs and gives you accurate weights that would improve your output.

Changes were also made to levelling in earlier content with Legion's 7.3.5 patch. The level-scaling tech introduced in Legion not only be continued in the new continents of Kul Tiras and Zandalar, but was also be applied to content from prior expansions, allowing larger level brackets for lower level zones. Further, as previous expansions are now included in the base game, the level ranges for those expansions are now broadened, allowing players to spend more time leveling in preferred expansions and avoid others entirely. Some examples include a zone like Westfall having its level bracket (at 10–15 as of Legion) increased to 10–60, whilst continents such as Outland and Northrend sharing a 60–80 level bracket. The aim of this change is to encourage more player choice whilst levelling and to allow players to experience the full story of a particular zone without overlevelling the relevant quests.

As the battle for Darkshore begins, both the Alliance and Horde are blindsided by a new development: High Overlord Saurfang, who had been defeated and captured in the Battle of Lordearon, has suddenly escaped Alliance captivity and is on the run. Sylvanas sends Horde Champions to track Saurfang down, ostensibly to extract him. However, it quickly becomes apparent that the search party is in fact an assassination squad, as Sylvanas suspects Saurfang of colluding with the Alliance in an attempt to dethrone her. While some Horde champions choose to side with Saurfang and help him escape the assassins, other champions remain loyal to Sylvanas and report Saurfang's and the dissenting champions' treachery to her.
-Global Cooldown- Almost all spells are now on the global cooldown. This has slowed gameplay down quite a bit and you won't get to use the full potential of your spells cooldowns. For example, you cast a spell that increases your damage for 15 seconds, after the global cooldown and you're able to cast again, you now only have 13.5 seconds to make use of the remaining time. There are far too many spells on the global cooldown that shouldn't be.
Stormheim is the zone you want to start it. For some reason Legion treasures are not worth any experience like they are in WoD...except in Stormheim. I haven't been able to find out any reason for this, and it's possible it may get fixed/nerfed at a later date. But for the time being you REALLY want to jump from treasure to treasure to augment your quest experience. 

And... that was it. New NPCs offered a glimpse of some truly amazing armor and weapons, none of which are currently available to players (and datamining suggests it may be a while, if ever, before they are.) There were no new appearances for players to farm, no items or pets or toys or titles to obtain, no achievements to complete. There was no repeatable, truly farmable content.
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.
-New dungeons- About 3/4 are fairly decent, not too long not too short, but none of them are compelling, none make me say to my friends and guildies, "Hey, let's do this instance, I love the theme and encounters." They're dull but tolerable. The other 1/4 of the dungeons just aren't fun and you will groan when you get a mythic Keystone for the Underrot, the snake temple, or Waycrest Manor. Waycrest Manor is actually one of the better dungeons, however, with the new Infested affix, Waycrest Manor suffers from many game-breaking bugs that end in the entire instance being pulled due to doors not properly working as intended. 

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.
At 98 you have the option to drop what you're doing and return to your capitol city to start the quest for your Legion Artifact weapon. However, I do not believe this is necessary to do right away unless you're struggling with kill speed in your current gear. I would recommend waiting for a natural pause, such as hearthing to repair and clear your bags. From 100 to 107 you won't even really fight mobs that often; only just enough to clear the way to any treasure you need to pick up.
I just decided that I would simply finish leveling my hunter the hard way, but when i can get heirlooms ill make a warrior and follow your guide to 80. I definitly want an 80 warrior for cataclysm... seeing as worgen warrior is going to be a crazy tank! By the way, is using heirlooms with your guides ok? And what class should I be for a tank? I will obviously be switching to worgen anyway but i would prefer best tanking until then. Thanks Jame!
-Global Cooldown- Almost all spells are now on the global cooldown. This has slowed gameplay down quite a bit and you won't get to use the full potential of your spells cooldowns. For example, you cast a spell that increases your damage for 15 seconds, after the global cooldown and you're able to cast again, you now only have 13.5 seconds to make use of the remaining time. There are far too many spells on the global cooldown that shouldn't be.
Unfortunately, the BfA prepatch took away more than usual--having an entire expansion balanced around an ultra-powerful weapon that abruptly turned into a dead stat stick made the end of Legion particularly depressing--and offered very little in return. The patch didn't flop because of bugs; it failed because it's boring, unrewarding, limited, unambitious, and actively feels like it's punishing players at a time they should be celebrating.
I do not recommend going for TBC, although I remember Hellfire peninsula to be decent, everything else is rather slow. Instead go for WotLK, Borean Thundra gets you levelled very fast, and then you can head straight for Icecrown at 67, which is also insanely fast, although admittedly has a few elite quests. You can go to Sholazar Basin alternatively. 2 zones should get you 60-80 no problem.
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