It's ok if we just agree to disagree. It's easy to look at the numbers without a sense of what he was up against, but it wasn't until the end of the season that we saw Murray dealing with defenses that even resembled what AD runs up against all the time.
The fumbling thing, I'll grant you, is a big issue. And one of the big reasons I don't want to overpay for him.
And you're right that the actuarial table says he'd be too risky a signing. I know it's a double standard to apply that age and wear/tear argument to DM and ignore it for AD. I'd still do it, anyway, at a moderate price.
Basically, I believe there are measurements for comparing the two backs that aren't unpacked fully in the total yards data, and I think Peterson's 2013 season was proof to me that the guy is, physically, a rare athlete. I'd take the risk on him where I wouldn't on most other players.
But I completely understand why other people wouldn't. I don't normally buy arguments based on other posters' eye-ball tests alone, either. Just saying, if it's me running the team, I'd place a long-odds bet on AD any day of the week.