Im biased, but i LOVE my M1009, and would never look back. They are excellent trail rigs, but of course, we all want 1 ton axles (ive got a set of K30 Dana's in the wings) but the question is do we NEED 1 tons. My M1009 has never gotten stuck, and never broken a suspension part, although the springs are worn out. Although i dont wheel the wee out of it, basically some offroading, trails, creeks, and mild rocks (think pebbles). I ran 33's on it and had a blast. In 4 low i could get through just about anything i ran up against, again, no sand, no major rocks, no competition stuff, but i did get it up to the "crease" in the body panels in muddy holes a few times. Only thing that ever broke was a battery came loose and took out the radiator. I managed to plug the hole with a wine cork, fill it with stream water, and drive it home. OH, and with those 10 bolts with 3.08 axles, 33in tires, the HD TH400 and the 6.2 diesel, i could effortlessly get 20+ mpg on the road to and from the trail.
The only, and i mean ONLY reason im upgrading to 1 tons, is vanity really. I wanted to run H1 beadlocks, so i needed big tires, which means i needed clearance, and DRW axles to fit the H1's without spacers, and i want to eventually do some more serious wheeling. But for what ive actually used the truck for, and as a general use, all around truck for camping, trail use, moving furniture, driving to the beach and all that, the M1009 is IMHO perfect as is. maybe a 4in lift and 35's to be the cherry on top.
So it really all depends on what youre gonna use it for.