I do believe there is no substitute for running freely around a room, absolutely, and I let nibbles do the same thing with a lot of supervision! But I think the balls are great for some inbetween time. Of course they also need to be supervised even when in a ball.
Each hamster is going to be different. When I can leave the lid off of my ball and he still won't come out ..... he can't dislike it that much!
