Levelling speed and zone sizes

I realised today while flitting the length and breadth of Zul'Drak that I completely skipped the Grizzly Hills zone. I'm now level 78, nearly 79, and the content of Grizzly Hills is more suited for 73-75. I also missed out on seeing various instances at an appropriate level, thus missing out on a decent challenge.

I first landed in the Borean Tundra and worked my way through all that. I didn't leave until I got the Nothing Boring about Borean achievement. I then spent many hours exploring as much of northrend as possible, a challenging task for being only lvl 72. I then completed the I've Toured the Fjord achievement and dinged a bit more. Then the Might of the Dragonblight fell too, I got my winter flying, finished exploring the rest of Northrend, and headed to Zul'Drak to continue levelling.

It's taking about one night per level, which is awfully fast, and I'm not alone in this. I'm out-levelling zones before I've fully explored them. I'm glad there's more than enough quests per zone to level and I don't have to mindlessly grind mobs before I'm ready to go to the next zone ... but the zones are still too quick.

One downside of this rapid levelling is that my guild is widely scattered across the levels and the zones, which means we don't get to play together much at all. Another downside is I'm missing out on hitting the various instances at the appropriate levels, meaning they present no challenge to me. It feels like I'm just boosting others, blech. Also, all the zones have great terrain and features and hidden nooks .. but I'm missing out on immersing myself into them - a dozen quick quests here, a dozen quick quests there, and I've moved on. There's also a huge number of stories going on in each zone, many with an underlying theme or greater story arc, but with the speed of levelling they're just not sinking in. More the pity.

Hmmm...