I've literally searched for years for the perfect shoe and I think I've found it.  I have a problem where when the back of the shoe is too high it rubs against my achilles.  I've searched all over for a mary jane that was stylish, yet goes with any outfit, and I had an extremely difficult time finding anything that met that criteria, let alone anything comfortable that didn't rub my achilles raw.  I went into a Takken's shoe store on a whim one day thinking if I have to get a shoe that's comfortable I guess I'll just have to settle for some ugly walking shoe.  I went in and the first shoe I noticed was this Dansko Tacey XP style.  I thought "its too cute to be comfortable".  I was totally wrong.  The back of the shoe is just short enough not to rub on me, but not so short that it completely slips off my foot.  The Dansko shoes are designed to slip a little in the back and provide a roomy box for the toes.  At first I didn't think a shoe that slips so much would be comfortable, but I've been walking around in them for 2 days and have not had any rubbing, nor has the shoe slipped completely off.  I also find that i haven't been clenching my toes in order to keep the shoe on, so my feet feel extremely relaxed.  The XP padding is really comfortable and offers a lot of arch support.  Apparently I have pretty high arches, so these  are just what I need.  I was told that nurses buy these shoes and now I see why.  You could literally walk around in them for 12 hours, get home and not want to take them off.  I highly recommend them.  And the best part is that I can wear them with a nice dress or in jeans and they still look great :)  I probably won't need another pair of shoes for at least the next five years!  the price is up there, but its totally worth it if I don't have to go shoe shopping ever again for the next half decade, especially with my stringent criteria for a proper shoe.