I have the Nine West wedges now! however, haven't worn them yet. They are lovely! But I was just wondering, the ones who have them too, how long are you able to walk in them, and do your feet slide forward in them? Will they stretch? That usually happens with me. I can wear both a size 7 and 7.5 and my friend wants to give me her 7 for my 7.5...Should I do it?