I've had mixed success with two pairs of Merrells. The first was a pair of Moab Ventilators that I tried over 10 years ago. While they felt great in the store, I never could tolerate being in them for more than a short period without bad foot pain. But that's a problem with my finicky feet, not with the shoes. My second pair of Merrels is an all leather casual shoe that has worked really well for me for years now. I wore them all day at work today and just got back from a three mile walk in them tonight, and my feet are feeling fine.
Since my bad experience with the Ventilators, I've kind of stuck with Asolo Fugitive GTX light hiking boots to keep my feet happy, going through about a pair every 600-800 miles (which was about yearly for awhile), not because they're totally thrashed, but because once the sole gets worn down so much on the heel I have to quit wearing them or my feet, ankles, and knees pay dearly. I haven't been able to figure out a durable repair that would allow me to get more life out of them, either. About a year ago I rounded up all the "old" pairs of Asolos and gave them to my cleaning lady. She said she had no problem finding good homes for them and couldn't believe I was giving away "new" boots.
This summer at REI, the guy talked me into trying a brand called Oboz. I'd never heard of them and he said they're some new company that's gaining a reputation. I bought their Sawtooth model and wore it all over Greece for a month and my feet felt awesome, every single day, and I didn't even have to put in the usual $35 SuperFeet insoles, either. That doesn't happen often for me. They're the happy medium between the Merrell Ventilators, which were very cool but not very supportive, and the Fugitives, which are very supportive but a bit hot and bulky.