I'm 6'1, 200 pounds, slightly underpronate, average 40 to 50 miles per weeK; I have these running shoes for 4 months and I'm happy with them, although I believe the cushioning isn't the best for long runs and a heavy guy like me. I rotate it with an ASICS NIMBUS 12, doing my marathon training.

I think the fitting is awesome, my feet are confortable inside and I never had such comfy shoes. Well, but since I'm a big guy and once a week I do a long run, the cushioning isn't as good as its competitor NIMBUS 12. I think the cushioning on ASICS is better. Whenever I run more than 12 miles with Glycerin, my knees sore, which it doesn't happen with the NIMBUS. Saying this, its responsiveness is perfect and if I have to run a race up to 15K, the Glycerin is the one I would use.

Another issue for me is that after running 150 miles with them, I already have some signs of wear. I thought it would take a little longer to show this, but since I'm pounding the asphalt with 200 pounds over it, I cannot say it's its fault.

I'd buy them again, but only to run shorter distances up to 12 miles; Brooks is releasing next month the new Glycerin 9, which supposedly would have a better cushioning.

If you don't plan to run such long distances, the Glycerin 8 is a very nice option for running.

UPDATE JUN 2011:

Although I really like how comfy my feet feel inside these shoes, it wasn't cushioning enough for me. I ran 200 miles and I started to feel my knees. That didn't happen when I'm wearing my Asics Ninbus12. Maybe that happen because I'm heavy, but I need something more protective. I'm still wearing the Nimbus together with the New Balance 1080. They both seem to be more cushioning than the Glycerin.