I haven't used these yet, and will try them in the next couple of weeks on vacation, but the fit is perfect - my 7.5 women's shoes and my husband's 11.5 men's shoes both fit perfectly true to size, with little to no room for our feet to shift around.  This is important if you're looking to SUP, so that you have a very sturdy base.  The shoes are extremely lightweight, and look to be very sturdily-constructed; I fully anticipate that the construction will allow for excellent drainage.  The style is really nice, these don't look like the water shoes of my childhood, and I really like the dark gray color.  I'll try to remember to update after actually using them on vacation.

UPDATE: tore up my shoulder before actually SUPping, so I cant describe how these work in that regard. My husband and I wore these to play in the ocean, though, and these did let a bunch of rocks and sand in the shoes. So, while these were great to prevent us from cutting our feet on loose glass or sharp shells while walking in the sand, that protection wasn't extended when we were being beat by the waves.