I have both. The conure has a play top, whereas, the cockatoo has a dome top.
I'm able to hang toys, etc. inside of the play top as the clasps fit between the tray on top and the bars which act as the top of the inside of the cage. As Michael mentioned, having a play top does prompt the conure to want to return to the top of the cage whether it's something I want or not. The cage doesn't get much light from the top but is positioned where light does get in from the sides and Bijoux can see outside.
The space in a dome top is great for hanging large swings/boings. I do not allow the cockatoo to get on top of the cage because I don't want MissChief perched above me. I do, however, let her perch on the opened door as she doesn't want to stay on the play gym.





