Well we used EVERYTHING: Jumperoo, exersaucer, push walkers, ride inside walkers and DS is a running machine now though he never stayed in those things long. It was more about fun, in short spurts and very closely supervised.
I never use things like that to "babysit" I think that's where the danger lies. I can't speak to the developmental issue but I can see why long periods of time in those things might not be a good idea.
Then again Fadzi I also let E play in the sandbox, I'm an old fashioned girl (as my ID specialist sister runs around after E wiping his hands!)
