Fit and feel

My feet pose quite a challenge for most shoes, as they are wide (US "E" width), and have very high arches. These shoes felt great in the store, with only a few minor issues apparent at the time, which I had expected to disappear with use. What I didn't realize is that these shoes don't have the usual break-in period found in most other shoes, and so those problems never went away. Most people probably won't have the same issues I had, but keep this in mind when trying Merrell shoes. On the positive side, even though my feet tend to sweat heavily, the excellent ventilation in these shoes keeps them relatively dry.

Field testing

I tested these shoes in a wide variety of conditions. While I initially purchased them for dayhiking and ultralight backpacking, I ended up using them as "everyday" shoes for four months in the winter while visiting Calgary, Canada, since the other shoes I had brought weren't up to the snow and ice.  Considering it wasn't what they were designed for, these shoes handled Canadian winter conditions very well. This use comprised the bulk of the miles I put on these shoes.

I used these shoes for a lightweight overnight trip in Point Reyes National Seashore, as well as a few dayhikes at the same location. Tested terrain was easy to moderate dirt paths, sandy in places, with occasional bushwhacking. The shoes handled all of this well, and the elastic collars kept out the worst of the sand and dirt. The weather was dry with no rain, and only a small amount of mud, which might otherwise have posed a problem for the mesh. On the longest of my Point Reyes dayhikes (10 mi / 16 km), the soles of my feet were quite sore, although I didn't have any blisters.

More recently, I tested the shoes on two dayhikes on steep trails in Mount Diablo State Park. These trails had many stretches with loose dirt and gravel, and some short rocky bits. Ascent was no problem. On the descent, the shoes did quite well on the solid rock, but only average on the loose stuff, slipping and sliding in a few places. During the descent, my feet would occasionally slide forward far enough for my toes to touch the front of the shoes even though the shoes fit snugly. This wasn't a serious problem, and may be an unavoidable consequence of the stretchy nature of the laces and shoe uppers. On the longer of the two dayhikes (14 mi / 23 km distance, 3400 ft / 1000 m net elevation gain), I did develop small blisters on the back of my heels and on my right foot's smallest toe.

The shoes have seen a range of temperatures from roughly 5 F (-15 C) to 90 F (32 C), and have kept my feet reasonably comfortable through all of it. Elevations visited with these shoes range from sea level to just under 4000 ft (1200 m). These shoes seem well-suited for light to moderate trails dirt trails with a light pack, and are also capable of handling a fair bit of scrambling in rocky conditions. I usually use the shoes in dry conditions, but have occasionally exposed them to rain, powdery snow, and packed snow. Although breathability usually comes at the price of water resistance, after applying a water-proofing treatment, these shoes were also able to handle short exposures to water without soaking through.

Durability

Lack of durability is my biggest criticism of these shoes. The right shoe has developed holes in the inner lining material in the heel area, and the left shoe shows signs of wear in the same place. This is after an estimated 250 - 300 mi (400 - 500 km) of use, most of it on gentle terrain.

Review Summary

Although generally a good shoe, I was disappointed by the amount of wear the Chameleon II Stretch showed after 8 months and roughly 250 - 300 mi (400 - 500 km). Unlike other shoes that need "breaking in", these shoes are what-you-feel-is-what-you-get. This is a good thing, but I found that minor fit issues I noticed at the shoe store did not go away with wear.

Pros: Excellent breathability, collar keeps out dirt, easy to slip on and off.
Cons: Poor durability, no wide sizes available, somewhat heavy for trail shoes.