You can find the full list on the WOW Classic forums, but here are some highlights. First, there are the annoyances. Blizzard never said that reverting to the game’s earliest stages wouldn’t bring with it some things they’ve improved upon since, after all. “Quests, objectives, and points of interests are not tracked on the map or minimap,” for example. Time to get out there and explore.
This was a good start, but there were issues with how the developers used to handle updates to the database data. Unlike the source code, for which Blizzard had archives for multiple branches of the game that could be worked on and developed as separate pieces, early database data was overwritten with each commensurate update. Thankfully, that problem was fixed very quickly after launch, and when we looked, we found data going back to version 1.12—and even earlier.

Nov 15 Can both versions be played at the same time? I would play a lot of classic wow in between the queue times in modern wow. I have to wait for queues for raids, wait for M+, wait for pvp queues, wait for mount respawns. During the demo, I had to decide if I wanted to test out the classic demo, or obtain new items on my modern characters. I would have played a lot more classic wow during my downtime in modern wow, but there was an issue where my modern wow account would be logged out of the game, if my classic wow account demo logged in. Pretty please, I would really like if the classic account did not log out the modern wow account and both could be logged in at the same time.Hunterhir8 Nov 15
It is a great advantage to start making some silver and your first gold coin at low levels already. Skinning is a nice choice here. Fast and easy way to gather resources, leather of all kinds while leveling for those who are at the race to level 60. There are many good spots to grind beast mobs and skin them. I like doing it as a Troll Hunter, trolls have a passive racial ability: + 5% bonus damage against beasts.
As it had been executed in Vanilla, Can Blizz launch the PvP rank system? As somebody who was wow classic gold around back then, and without needing to get overly hand-wringy, I feel that the position system itself supported some fairly unhealthy behaviors. That top rank took months of continuous grinding, and I mean constant, 10 to 12 hours each day, to the stage where people weren’t even functioning properly and everything out of that honor grind was excluded. There were things in WoW Classic that you had to forfeit your wellbeing and life outside of WoW Classic to obtain. 
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