You are running place to place correct and what just tagging mobs and moving on? I find I can't kill anything since I'm usually solo killing bigger mobs

Yep. Tag everything in p1/2. You get A little over 50k/xp per boss in p3. I usually killed around 5 (sometimes a couple more, usually no less).

It was consistently around a 20% increase in xp/hour doing p3.

I'm pretty sure it's faster to only do stage 1 & 2 until you have flying, then flying to big bosses with the group in stage 3 are very worth.

Yeah I don't friggin have damn flying hah I'll test it when I'm 60 shortly