Well, I didn't really think about it and I wore them in the rain. They soaked all the way through the bottom since the soles are just thin leather with rubber patches on the sole and heel.
On the right foot the seam in the back where the leather is sewn together sometimes bugs me.
Other than those two issues I absolutely love mine. I had a HORRENDOUS experience with Sue London's website. I think they have the most atrocious and unforgivable customer service. I will never buy from them again. I can't say anything bad about the shoes though. In fact, I regulary search for them on ebay and Bliss. Actually, I do have one complaint. I think they are overpriced.
I would actually try Sue London. I love them I just can't get over how mad I am at the people that run the company. It's hard when you love a product but hate the company.
Call Bliss. They have Sue London slipers on sale but showing up as unavailable for immediate shipment. Maybe if you do a phone order they can find a pair for you. There are 2 pair on eBay now in a size 6. Sue London recommends sizing down if you are in between sizes. I tried on an 8 and a 9. I wear a 8.5 but my feet are a bit wide. The 8 was way better! Whatever you do be warned about trying to order direct from Sue London. You will probably be sorry you did.
I have heard really good things about Repetto and French/London Sole shoes. I have never tried them but they get rave reviews on this board.