My cats are large cats, not overweight but long and muscular. When they pounce the floor moves. Having said that they LOVE their cat tree. It takes their full body thrusts with stride. They run up and down the cat tree all the time as they chase each other. I was worried when I read some of the reviews that the cat tree can be flimsy. This is certainly NOT our experience. The best part of this tree is that our youngest cat now prefers to scratch the rope posts vs our furniture. We love this tree!