The cage extends to twice the width shown in the photo and fits three perches, a ladder and three small to medium sized toys while leaving enough room to freely turn anywhere. I thought that'll be large enough for one bird.
I take him out twice a day to roam around the apartment, which, based on the reading I did, should be enough to provide needed excercise and interaction.
I really hope I am not creating a sad bird O.o Thanks for voicing your concern. I'll be sure to have a careful eye on his happiness.