I've run and hiked in these about 20 miles over the last week, so I wanted to post some initial thoughts. I live in Anchorage, Alaska where it has snowed and rained a couple inches over the last two weeks, resulting in snowy, slushy, and very icy roads. This area of Alaska inexplicably (in my opinion) does nothing to treat their roads, so we have a mix of smooth ice in residential neighborhoods, ice with a mix of rough snow on sidewalks, and hard-packed snow on trails, which has given me a chance to test out these Yaktrax in a variety of conditions. The yaktrax give stability in all, but they definitely work best when there's rough snow and occasional patches of ice on the sidewalk. I can feel them biting into the snow and gripping as I run. I probably could get away without wearing the Yaktrak in these conditions, however they give me extra confidence when I'm crossing into intersections with smooth ice and I don't have to slow down to a careful tiptoe across the ice. When I lived in the midwest and east coast, I never bothered to get Yaktrax for running because I could just slow down a bit and find paved/salted parts of the road or run through snow banks. Here, it's all ice, so some sort of traction is a must.These also help me grip as I walk downhill in my smooth-ice neighborhood. Without them, I would not be able to walk in the neighborhood at all without falling. With them, I walk very carefully out to the main roads and sidewalks, but I would not dare run on the smooth ice even with the yaktrax. I bought unigear microspike/crampons at the same time and feel they're overkill for the current sidewalks, but would probably let me run on the smooth ice in the less traveled neighborhoods.The one day we had really slushy snow, I felt like I was running in sand and took the yaktrax off in frustration. I immediately felt the difference - without the yaktrax, I could hardly move forward in the slush. With the yaktrax, while I was definitely getting more of a workout than normal trying to move through the slush, I was able to get purchase on the slush to move forward.A few issues regarding fit - I purchased a medium and I wear a women's size 8.5 in regular shoes and winter boots, 9 in running shoes and hiking boots, and these fit over all of them. The hiking boots might have been a stretch, but it did work in a pinch on flat hiking trails. The first time I wore them, I realized I had put them on my running shoes backwards, so the next time I wore them the correct way (as indicated by the writing on the heels and toes). The coils kept sliding off my shoe towards the inner side of my foot and every 2 minutes, I'd have to fix them. I finally just started wearing them backwards and have no issues with the coil slipping off the shoe now. If you're having issues with the coils slipping and sliding off your sole, try wearing them backwards. Finally, I find that as I get tired, my heels tend to strike my opposite foot. With the yaktrax on, sometimes the coils hit my ankles, so I find that wearing thicker socks helps from hurting them. I don't think they're sharp enough to cut or bruise my ankles, but they irritate them with thin running socks on.The coils and rubber don't seem to have worn down visibly yet, but given others' reviews, I don't really expect them to last past this winter season. I don't wear them with the velcro "performance" strap, because they seem like they put so much tension on the rubber, it could snap. I haven't had issues with them falling off the shoe without them. For less than 25 bucks (far less than a gym membership), this seems like a small price to pay to keep me running outside whatever the weather brings. I'll update this review if they break down in under the season.Pictures: wearing yaxtrax backwards on running shoes, yaktrax have no visible wear after 20 miles, yaktrax let me walk carefully in this smooth icy neighborhood, and yaktrax let me run with stability in sidewalks covered with rough ice and snow.