All 4 of my birds use every bit of space in both their cages. I have it set up proportional on the upper part, and lower part and put all sort of foraging goodies and foot toys on the bottom. Mine are on the bottom more than the top actually. I'll take a picture of mine today and show you how I used my space, cause it was bigger than I thought it would be too when I first ordered it.

Looking forward to seeing your cage set up...
hope it will give me some idea's