Decrease in leveling zones.

[IxilaFA]

Humbly disagree. When leveling the first time, I full cleared Gorgrond and was a high enough level to skip Talador outright, so in my second run through, I did the opposite, full-cleared Frostfire, did a couple instances and the intro to gorgrond, then left and cleared Talador.

You could also say that while the questing is largely the same between zones, there's lots of little goodies to collect that're worth a buck or two.

Exactly this. I full-cleared FFR on my main, and then did all of Gorgrond and then did some of Talador, all of Spires, and some of Nagrand. Of course since it was my main I eventually went back and did every questline.

Now on my alts I do maybe 1/3 of Frostfire Ridge, half of Gorgrond, a little bit of Talador, a little bit of Spires, and part of Nagrand. The garrison leveling potions help speed up the process a lot. If I really wanted to change my leveling path I have ample opportunity to. The leveling this expansion is far and away better than MOP or Cata, where you had one path to take every single time, with only a little bit able to be cut depending on how many dungeons you did inbetween.

[Vanaline]

Draenor has had, by far, the best leveling experience for a solo player of the game thus far. I just wish they'd offer up some options for more difficult progression or group progression.

[Morthulo]

I enjoyed the leveling experience in WoD, but it I had done it 10 times too, I guess I would hate it as well.