I actually just got a set of Calientoes a week ago. So far in a week's worth of riding they're holding up pretty well. I just keep in mind to not skip my toes or drag my feet on the ground when rolling to a stop.
I am using them on a pair of Specialized Tahoe shoes, sized 14 US, with Crank Bros cleats. The large/XL size is a pretty tight fit on my shoes. Over the course of about 6 miles the back end of the cleat hole tends to slide forward along the sole of the shoe towards the cleat, but it has yet to interfere with clipping in/out yet. They do tend to gather mud/snow around the cleat, depending on how sticky it is.
Overall, I'm happy with them so far, and they do work well for keeping my toes warm.