I have firmed my butt ...!!! YAAA it took a lot of work.. BUT DONT DISCOUNT FLOOR WORK.. I USE 10LB ANKLE WEIGHTS and do kicks-- side kicks --leg raises.. etc... along with lunges .. squats.. and the high step really helps hips and butt...
I make sure i work out my lower body at least 3x's a week... IT IS THE HARDEST PART TO TONE!!!!! (for females)