Anon Partsunknownwrote a review of Ruffwear Bark'n Boots Grip Trex - Set of 4 on October 6, 2011
Heavily made, easy to fit, and apparently comfortable once she got used to having shoes on.
Our mastiff was getting cracks in her pads, but these boots protected her feet so well, they disappeared. They fit and stay on quite well.
As to wear and durability, we'll just have to wait and see.