I wear only Vionic shoes or add the insert to any other shoe.  I wish I could wear the Vionic flip flops year round but as I live in Michigan that might not be wise.  My issue is with the right shoe/foot.  My toes feel squished.  The left shoe is very comfortable.  I've been stretching out the toe box on the right shoe to see if that helps.  The support of the shoe couldn't be more comfortable.  Great arch support that has a little give to it so you don't feel like you have a rock under your arch.  I normally wear a 7.5 and bought a 7 in this because I know Vionics run large (all my sandals/slippers etc. I buy size 7).