As with most Merrell walking shoes, I found the MQM Flex 2.0 GTXs to be comfortable straight out of the box. Due to the trainer-style design, they fitted like a glove and I immediately felt at ease with them on my feet. They were true to size for me, there was no rubbing or discomfort anywhere and I was immediately eager to get out in them. They were pretty lightweight too. At 708g per pair, they were far lighter than many other pairs of approach shoes I’ve owned in the past, which made me feel fast, light and nimble on my feet.

Merrell MQM Flex 2 Hiking Shoe Review | Switchback Travel

In terms of fit, a few customers say that the sizing runs slightly large, but the main thing to note is that Merrell has opted for a particularly roomy toe box. The idea is that you have room for your toes to splay while walking / running. Most reviewers agree that while this might feel a bit odd and oversized when you first put these shoes on, the design actually works well in practice. Merrell MQM Flex 2 GTX hiking shoe review: performance and comfort

The MQM Flex’s lightweight hybrid design also puts it in the crosshairs of one of the top trail running shoes: Altra’s Lone Peak 5. Right off the bat, we'll note that this shoe has developed a strong following among thru-hikers with its supportive cushioning, wide toe box, and solid traction. Altra even includes nice touches for long-distance hikers like attachment points for a pair of gaiters. Compared with the MQM Flex, the Merrell has the upper hand in durability, but we give the advantage to the Lone Peak because it’s more comfortable, weighs around 3 ounces less, and has a more proven outsole. These trail running shoes also offer great stability, which once again boosts both confidence and speed. Because of this, I found myself able to focus less on the trail and instead soak up the scenery around me. Many times when trail running, I end up being so cautious about the trail that I forget to look around and enjoy the place I’m experiencing. The MQM Flex 2 made it easier to take my eyes and mind off the ground and commune more with nature instead. One of the things that first caught my attention about the MQM Flex 2 is how comfortable they are on your feet. Not only do they provide plenty of cushioning, but they are also designed to move with your foot as it adjusts to the changing terrain and environment. The aforementioned Quantum Grip sole flexes nicely as you run, enhancing the runner’s connection with the ground at all times. The weight of the shoes has consequently increased from 648g to 708g, reflecting a sturdier and more durable build for the 2.0 iteration, but the extra 60g per pair isn’t particularly noticeable on foot. Another change is that the 2020 version is 100% vegan friendly, reflecting the growing consumer demand for ethical products.

Merrell MQM Flex 2 Gore-Tex Trail Running Shoe Review Merrell MQM Flex 2 Gore-Tex Trail Running Shoe Review

That said, adding a Gore-Tex liner to a shoe—or any garment for that matter—will cut down on the overall breathability of that product. Gore-Tex has come a long way towards improving breathability in general in recent years. However, most waterproof membranes still tend to have a hard time keeping moisture out while allowing perspiration to pass through too. Because of this, I found my feet occasionally getting warm and sweaty, but usually, this only occurred on warmer days. Because of the comfort and stability that the MQM Flex 2 bring to the table, they not only make good trail running shoes but light hiking shoes too. This versatile set of footwear also makes a great running errands shoe or working around the yard shoe. Serious runners will most likely want to reserve them for that activity alone, but others will find plenty of other excuses to put these comfy shoes on their feet. Big Shoes to Fill The rest of second-generation MQM Flex is reflective of the original: Merrell did a great job mixing open mesh along the top of the shoe for ventilation with tightly woven mesh and TPU reinforcements in the lower areas most prone to tearing. TPU film and a small rubber toe cap also combine to provide decent protection around the front of the foot. In about four months of use, the uppers are holding up very well, and the same goes for the lacing system and interior of the shoe. All in all, the changes to the 2.0 version are incremental tweaks and improvements, rather than a wholesale re-design, as Merrell have chosen to build on the solid foundation created with the original MQM Flex GTX product. I found them to be winners in the comfort department – no blisters or pinch points encountered – and versatile enough for a range of disciplines from hiking to trail running. For everyday adventures that weren’t excessively hardcore, I found them ideal and didn’t have any complaints.

The waterproof GORE-TEX membrane on these shoes worked well, and I was able to submerge my feet almost all the way up to my ankles on numerous occasions without any water seeping in. In most cases, I prefer non-waterproof shoes because they breathe better and dry faster. But I’ll admit that having the ability to walk straight through puddles rather than hop-scotching around them was a nice benefit on shorter hikes. We like the fit, which is spacious around the toes, but you can cinch it down nicely around the midfoot and heel. Merrell has a long history of making sturdy, supportive, and well-designed hiking boots, earning themselves a huge fanbase amongst casual and serious hikers alike. Much of those same sensibilities have carried over to the company’s line of trail running shoes, including the MQM Flex 2. In terms of stability and support, the MQM Flex 2 more closely resembles a burly trail runner than a typical hiking shoe. The heel cup is fairly solid, which helps keep ankle rolls to a minimum, but it doesn’t have the wide footprint or planted feel of a shoe like the Moab 2. That being said, I had no complaints while hauling a load of just under 30 pounds or lighter weights while day hiking. If you’ll be carrying much more weight, however, or just prefer a sturdier shoe, there are plenty of more capable options. For low-tops, the La Sportiva Spire GTX is almost boot-like in its stability, and Salomon’s X Ultra 3 also offers better support.