We actually bought this bouncer at Target last weekend... and once assembled, promptly returned it. The "automatic bounce" feature was more like a pathetic bob; my kid was bored. And when she kicked her legs, or when we tried to manually give her some real bounce action, the counterweight responsible for the bob sounded like it was hitting the top and bottom of its plastic casing, making a terrible, non-soothing racket. Maybe we had a faulty one but I can't see this being very useful. The design of the frame also makes it less convenient to manually bounce than most other bouncers, which typically have supports in front that you can tap with your foot.
We ended up buying a far more basic model and she's much happier. I should have known better than to think a battery-operated device would be strong enough to actually bounce.