We have had three installed in our home; front & back doors of our home and side garage door.  Started with only one in the front door but it was not only attractive but easier for us to lock and open rather than fumbling around for keys.  No more added  expenses of replacing locks and making copies of keys because friends, relatives, house and pet sitters don't always remember where they put our keys and/or never return the keys.  What an attractive and cost effective addition to our home.