Yes I think so too

Just as a comparison, I made 6k questing in BEM, SMV, Netherstorm because I hit 70 in Nagrand. Some of them also come from selling DE's greens, herbs skins etc. So they're not all quest rewards per se.

Right now my main is 80 and he's still at Zuldrak, with Sholazar, Icecrown and Storm peaks untouched. But it's a little hard measuring my total gain, because I've been spending a LOT of gold for gems and enchants for Naxx. But it pays off. When you're geared in Naxx epics, questing in Zuldrak becomes MUCH easier.