Kyle M.wrote a review of Petzl Vasak 12-Point Mountaineering Crampon on February 1, 2018
Familiarity: I've put it through the wringer
These are solid all around, versatile crampons that don't excel at much in particular. For basic snow travel, they are a little heavy but do well. Can attach to running shoes or mountaineering boots, and I really appreciate this versatility. However, I've since upgraded to aluminum Grivel Air Tech Lights for fast and light ascents. They've held up well on rock and dirt but watch for the screws to loosen over time.
Other reviews may say these don't climb vertical ice, but they do quite well. As a complete beginner, I was able to climb WI4 with these crampons, mountaineering boots, and some archaic Aztar tools (which people also say cannot climb vetical ice, but I beg to differ) that I modified to be leashless. The flexlock felt solid and never seemed questionable. Granted I've never used true ice climbing crampons and they're probably loads better, but for an aspiring alpinist, these are all you need. If you're looking for one pair of crampons to take you from running peaks in the summer to some moderate ice climbing, this is a great pair.