The best part about classic will be that the game will go unchanged for years and years and years (for the most part). I love the idea that I could play for a weekend, stop for a year, and when I log in my progress will still be relevant. I love the idea that my lvl 30 toon will still be half-way leveled a decade from now. Everyone talks about classic as if it's only for the hardcore, and that everything will revolve around racing to the endgame.
Thing is, I've started playing RPGs/MMOs just because I want to level a character, live in a fantasy for a day, get excited about loot, etc. But it's never been as awesome as WoW. The new streamlined leveling is just lame, and I find myself running to the endgame on the latest expansion with my main toon.
I'm actually open to a 'pure' vanilla, or some improved version. If they do change it, FFS don't change the gearing pace. I actually wouldn't mind a group finder, some QOL improvements, a little spec balancing, achievements, etc. Just keep the leveling and gearing pace similar to classic, and I'm happy.
Yes I get that changes may have externalities that may speed up the game, but no free XP, no free loot bags, no badge gear, and so forth. I just want to work on a character for decades, and know that my progress won't be washed away by a new xpac.
I sincerely hope it's F2P, or a one-time box fee. And someday, I hope that WOW classic is just a browser game =)