My wife usually buys size 5W shoes and occasionally suffers from plantar fasciitis. She also has a low arch. Purchased a light blue Small (size 5-6.5 for women) version of these sandals to wear indoors, to cushion her feet while walking on hardwood floors. The sandals are as soft as advertised, but it is about 1.25 too long at the back for her, which could cause her to trip. She's debating on whether to wear them out onto a hot deck to see if they would shrink up around her feet for a better fit.

They work for spa shoes, but they run a little big. I am keeping them anyway.