Yesterday Kungen (former guild leader of Nihilum, one of the top raiding guilds in vanilla and the best guild in TBC) had a great stream talking about Vanilla and why it would be good for blizzard and its customers to implement legacy retail servers.
He also talked a lot about how WoW was back in the days, from a top raider pov. (opening the gates of AQ, raiding in vanilla, etc.)
I only started raiding seriously in wrath, so it was a lot of fun to see how different it was (the whole server collaborating to get the materials for the AQ quest, for example)
very entertaining stream which shows just how different the game was back then, you can check it out here https://www.twitch.tv/kungentv/v/61755386
The best bits start around the 3 hour mark, when the petition hits 200k