I did an arm routine once following the same basic idea of supersetting 3 exercises and doing 4 sets like that.
I couldn't even move my arms afterwards, and had trouble driving home.
My question to you is this, how did you drive home : )
It sounds cool, maybe sometime I'll give it a try, but there's no way i'm going to do squats, the leg presses, then leg extensions at my current gym.
And I have a good reason, the leg extension is upstairs with the pansy ass eq and the free weights are downstairs. By the time I got up the stairs I'd fall over, lol.
Sounds cool though.