I was going to say that the most important part of having a cat tree is LOCATION! LOCATION! LOCATION! But I see others have beat me to it.. It's a big waste to have one, but not by a window. I have 3 in my house for my 4 girls and they are ALL by the windows...That's not counting the toddlers bed I have for them that is by a window also.

I can't imagine having 2 as active as those are..Giz was my "bad girl" the one that bored easily and was constantly into something and when caught in the act, she'd do that "Who ME? I am innocent" look.. She was such a hoot and I really enjoyed her antics... but she was calm compared to how yours sound..