Right up there with finding the perfect little black dress is finding the perfect hiking boot (or so I hear). I’ve gone through numerous versions of the latter in the past few years alone. This one is too hot. This one is too heavy.

While not perfect, the Keen Tempo Flex Waterproof Boot offered a comfy fit right out of the box, no break-in period needed, with a contoured heel and toe box and great tongue and ankle cushioning. The outsole proved grippy on the mostly dirt trails I traversed but could have been a better on wet rock surfaces — still passable, though. The waterproof membrane and repellent did their job as advertised.

The big selling point with this boot is the “bellows flex” incorporated below the laces, right in the area where many boots crack and weaken over time. According to Keen, the inset rubber bellows “requires less energy to bend, making each step feel a little easier.” And, truly, the bellows did its job. The boot felt flexible and fast, with no pinch in the upper foot that can occur with leather.

One complaint I’ve seen in reviews is that the boot’s material can tear in the area around the flex point. I’ve worn my pair on several hikes, maybe 50 miles overall, and indeed there is a small tear forming in the thermoplastic polyurethane (TPU) fabric that provides reinforcement over the ripstop base layer. However, this tear has so far not spread and has not impacted the waterproofness of the boot. Time will tell.

Bottom line: Comfort is the strong point with this lightweight, fast boot, but long-term durability may be a consideration for heavy-duty users. $180. keenfootwear.com

Author: Brad Kovach is the editor/publisher of Terrain Magazine.