This mentality right here is why leveling will never be done correctly and the classic servers will bomb.
Know what made leveling in Classic fun? It wasn't the abysmal rate at which you gained experience.
I saw Stormwind for the first time. That made Classic fun. I saved up 18 silver to buy a Tabard. That was fun. I ran to the Auction House to buy Searing Blade, my first ever Rare item. That was fun. I walked across Loch Modan, Wetlands, Arathi, Hillsbrad, Silverpine, and Tirisfal Glades to get to Scarlet Monastery to farm SM Graveyard for money to buy my first mount. THAT was fun. You get the point.
Leveling in Classic was fun because there was so much to do. Leveling was slowed down because there was so much to do. There were so many different personal achievements to obtain, so many different goals to strive for before raiding. Thats what made it memorable.
Increasing mob health and experienced required by some arbitrary value does not make the game more reminiscent of Vanilla nor does it suddenly make the game fun. Driving across country 30 miles slower doesnt make the trip more enjoyable. Stopping at various places and experiencing different things along the way does.
A long trip is fun because of the things you do along the way. Not because of the distance you travel.