The cloak is nice because you only need one of these instead of the previous cloak versions since the primary stat changes depending on the class it is used on. The on use trinkets for versatility, haste, or critical strike could be very strong if used together by numerous party members with the same trinket. Finally, the threat reducing trinket could be useful for solo levelers in dungeons with newer, non-heirloom geared tanks in order to not pull threat on some larger packs of enemies.
Certain locations in World of Warcraft – primarily inns, capital cities, and private instanced zones like your garrison or class order hall – are rest areas. You know you’ve entered one because your character portrait will gain a “Zzz” icon where your level is normally shown, and because you can immediately log out of the game instead of waiting 20 seconds.
For Alliance it's Lok'Modan, Redridge, Darkshore, Felwood, Stranglethorn (both parts), Plaguelands. Somewhere between 3 - 3.5 of these get you to 60 in like a 16 hours /played, if you queue for dungeons at the same time. I recommend dropping everything at 45 and going to Darkshore-Felwood if you didn't do them yet - they are literally the fastest levelling zones in the game right now, maybe only trumped by Silverpine.
War Mode: War Mode can be turned on at level 30 through your talent window, and will give you 10% bonus XP. You will, however, be attackable by players of the opposing faction, but changes have been made so that all players have a fair shot in a fight and even low-level players can kill much higher level players, and at least not get ganked and one shotted. Note: As of patch 8.1, you can get an additional call to arms bonus with war mode on if your faction is underepresented.
This level range opens a variety of zones from the Cataclysm expansion, which are spread across the game’s original continents, but it’s more efficient to head to the continent of Pandaria. You can spend the entirety of this level range exploring its uniquely themed zones and quests. The Jade Forest, Valley of the Four Winds, and Kun-Lai Summit are our picks, but all the zones are worth checking out.
PLUNDER THE ISLANDS OF THE GREAT SEA – Explore Azeroth’s uncharted isles in Island Expeditions. Battle in groups of three as you race against cunning rival intruders (or enemy players) to collect the island’s resources and fuel the war effort. Constantly evolving challenges await as you traverse frozen landscapes near Northrend, open the gates of an abandoned Gilnean castle, navigate a war between elementals, and more.

For reference, my previous best time abusing Method-0 in 7.3.5 was 32.4 hours(as show in the old thread). A difference of just over 8 hours; which isn't all that bad, all things considered. And I believe I made several errors along the way, which could be cleaned up in future runs. I believe that that gap could be significantly closed by using a monk's bonus, but I hate playing YMMV