Salt water sandals – your thoughts?

It is spring here in the southern hemisphere now, so I am starting to think about spring/summer shoes for my girls. N has well and truly grown out of the sandals she wore last summer and L's feet aren't big enough for the ones her big sister wore when she was this age. I had noticed salt water sandals popping up in a few modelled photos in the flickr pool so wanted to ask your opinions on them. They aren't readily available in New Zealand. Only a couple of brick and mortar shoe stores stock them and charge more than NZ$100 for them (approx US$65)! I can buy them second hand or new online though for a fair price. I used a printable size guide from the salt water website and N would need a size 10 (she is about to turn 4) and L would need a size 5 (she will be 2 in January). Those of you who are familiar with these sandals... Do they end up getting very scuffed? Do kids find them comfortable? Do they last more than one child? Is the open toe style ok for toddlers or do they just end up stubbing their toes? Thank you in advance for your thoughts. :)