Only a four because of the multitude of sliding doors.  But space and the bars were a decent thickness and strength.  If A&E could modify the fixture to make those door to one larger one similar to the elegant flights, that cage could easily be a number one selling cage for smaller birds.  I have two and each cage has a pair of green cheek conures.  There is no such thing as too much space (unless elderly, handicapped or injured in some way).