Gucci strappy sandals 100mm in black leather

These are probably considered vintage as I bought them at least 12 years ago.  Since then I never bought any more Gucci footwear as they are so uncomfortable and I am very reluctant to try more.  Somehow my feet seem to want to slide forward even though the shoes are just 100mm.  And they feel quite difficult to walk in.  Love the simple classic design though.  True to size.