I bought these to extend my cleat life after switching from Speedplays (with a metal cleat). I used to ride Look and walking on them for 100 yards would wear them down without covers. These go on easily and stow in your pocket when riding. Remember to take them off before you jump on your bike though :-)
Bought them to use on RAGBRAI. It's a 400 mile ride across Iowa. Choke points in each small town means you have to dismount & walk many blocks on pavement. These go on in a hurry, come off easily (peel them from the corner rather than the middle) and totally protect your cleats. Also useful when wandering into muddy corn field to answer natures call by keeping mud out of your cleats. Showed minimal signs of wear at end of week, though you should consider them an item which will need replacing eventually.
I dont always bring these with me on rides unless a stop with walking (such as For coffee or food or a spot where you have to walk bikes) is planned, but when I do, it definitely saves wear on the yellow cleat points that would normally contact the ground. Walking with the covers on is not particularly awkward, but you do get a clear reminder (and a quick laugh at yourself) if you try to clip in with them still on your cleats. Easy to get on and off once you get the feel for it.
These little cleat covers slip into my small fanny pack for a ride, and anywhere i might get off my bike while touring, i whip them out and snap them onto my cleats. No more worries about walking on pavement chewing up the precious soft plastic of my cleats!
I like destination riding for food. The covers are small enough to cary in my shirt pocket and they work great, They seem to be wearing well and stay on while doing short walks through restaurants. They even seem to stay on while walking on gravel. Fair price for a good product.
The Shimano cleat covers fit better (think snugger) than the other guys covers. With these covers I'm not always checking behind me to make sure one or both have popped off.