Cons: right foot fits quite snug around the strap. 5 hours later, I am actually energized and have 3 more hours to go. Overall love these! Overall very pleased with my purchase and seller! This would be good if you were hanging only really really light things on it. The grey ones with the white soles are the old pair; the black with black soles are the new pair. I would like to get them sent to me, please My husband and I set this up and there is a slight IQ test because the instructions were poor. The biggest design problem is in the heel; specifically the hard black portion of the sole that sticks up higher in the heel at the back than the soft gray part. The only possible downside I could think of is of course the smell from the initial unboxing of it, however that is to be expected, considering virtually almost every other extended mouse pad I had looked at had this.