I used Daniels for my 1st Marathon. I used his 2Q plan and maxed out at 75ish miles. I dealt with IT issues in both knees and had only 1 LR in the last 7 weeks going into the marathon. I ran 2:51.
For, my second marathon I used a Pfitz 18 week plan and maxed out at 95ish miles. Was able to stay healthy the 2nd training cycle and ran a 2:40.
For my fall marathon, I plan to max out at 105-110 and use Pfitz 18 week as a starting point. I will replace most of the Pfitz workouts with the Daniels threshold and interval workouts. I won't do all of Daniels MP workouts since MP runs don't seem to be physiologically more beneficial than a normal long runs. If I skip most of the MP workouts, I should have the energy to complete all of his threshold stuff at the paces I desire.
I really like the medium long runs in Pfitzinger's plan, but didn't find his workouts to be that interesting. Although, I think the Half MP LT workouts helped my fitness.
I found VDOT (based on race times, not measured in lab) to be a excellent guide to my training paces and predictor of my race times from 10k to marathon.