-PvP- Completely broken for some classes and I mean broken going from both sides of the spectrum, from classes destroying everyone, to classes that can't even kill another player. It's fairly common for a weak class to lose to a powerful class even if the weak class outgears them by 50+ ilvls. That's how broken PvP is and Blizzard doesn't seem to know what to do to fix it other than do blanket damage nerfs/buffs as those are the only changes we've seen.

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.
So tonight I took the plunge and thought hey let me buy a Zygor Guides subscription to see how it is. A guide backed by a subscriber base paying for a premium experience this has to be great right? I was wrong. I tested it by loading it up on the Honorboud Rep Guide. Cool it tells me to do World Quests and Island Expeditions. So far so good but hang on... What about the Wanted Quests? Those are by far the biggest boost to reputation. It did not mention them at all. So I thought that's fine it's probably because BFA is quite new. Loaded up a leveling guide on an alt. It was a complete mess. The guide was telling me to accept quests that A) would be horribly inefficient to level with and B) I already done. I also started noticing weird performance issues. Zygor was causing stuttering and FPS dips like crazy. So to close off I requested a refund and the person I spoke to did say I'll be getting one but we will see if that happens. Not getting my hopes up.
Once again, as soon as you hit 70 - I recommend to go and learn faster flying. This speeds up your questing A LOT, and is worth the time and gold. It will cost 4500 if you go to the capitol, or 5000 if you prefer Shattrath/Dalaran, because you will not have reputation with them at that point. This price will sadly be above what a totally new character can afford, if you don't have any Main. But you should go and buy flying as soon as you have enough money.

If you need the abridged version, because you’d rather spend an hour in a game than hearing someone talk about a game, you can also check out the excellent “New & Returning Player Guides” series from YouTuber (and World of Warcraft expert) Bellular. And you probably even skip the bits about ”how to purchase” or “how to install” the game, saving you even more time for new World of Warcraft adventures:
“I think that there’s a lot of gray in the game and in our world, right,” asked Cobo. “And so I think that tapping into that and making things reflect the complexities of the relationships that we have between these key characters and then the player itself, and having the player be able to experience that from their perspective, is really what is one of the strong connecting hooks of World of Warcraft.”
At the same time, a stat "squish" meant that players' gear level, health and damage were drastically reduced. Monsters' stats were similarly clobbered, though predictably, some lesser-known abilities immediately started one-shotting players. (On the beta servers, a simple toy allowed players to kill each other with one blow, with amusing results; but even on live servers, those bugs were legion.)
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.