Were you well rested during most of your leveling? Your leveling seems really fast, grats on that.

I have 4 shaman team I'm leveling atm, 3 are 52, one is 67, and I believe I have close to 5 days played on each of the 52's.

I've tried doing instance farms but that has seemed quite a bit slower than just clearing out all quests in a zone and only doing instances for the quests.

I don't have a tier 6 warrior to farm the instances with though so my runs have been a tad bit slower than what you're posting as times.