Speed leveling

OK so I am playing WOTLK and have never played alliance on WOTLK, only TBC back in 2008 So i thought I would give this a shot at a spirited pace, not hard core, and I ended up at lv77 with 25 hours played. About to jump on and finish it here in a minute but it got me thinking about how fast I could have gone, I did get hung up around lv 56 - 58 with some bad zones. Also havent used flying mount at all in Northrend and I had 1 BoA to start and a 2nd one later that had +10% XP I also played a lot without rested XP So I am guessing if I had done it hardcore fast I could go 18 hours with full BoA, always play rested XP and did the proper zones

do the BoA +10% stack ?

Whats your best time to 80, what class and what faction? I would think in theory the Mage has the best time to lv since they can Port to main cities AND use hearthstone.