Vionic's are my sandals of choice and I have several pair that I love. They have great support - a sandal you can wear all day.
This particular Floriana Black Croc style looks great and fit as a normal size 8, however, the straps are made of plastic with no backing on it. After one time wearing them, I had a chaffing and blister where the plastic rubbed. My other Vionic's have a soft backing on the straps that prevent that from happening. As much as I like the look, I have to return them. Poor design and so unlike  Vionic !!