Pros: Safe, great entertainment, good for baby's strength
Both of my girls have loved the Jumperoo! We put them in it when they could hold their heads up well and they love to jump. I like how this one has the height adjustment, otherwise their legs just dangle unless you put something under it for them to stand on. It raises and lowers easily and the seat also come off easily for cleaning. The toys and music keep them entertained when they are not jumping and it can be turned off to keep you sane! There is also a switch to control if the baby's movements turn the music on or if they hit the button to do it. I have never tried the Johnny/Jenny Jumpers because I didn't trust our doors to hold them! With the Jumperoo, you don't have to worry about that! I think I've only changed the batteries once in about 5 months, too. Even without the sounds, my girls have loved this thing. They seem to enjoy jumping and have spent a lot of time giggling in the Jumperoo! I have hauled it through different rooms in the house and while it's kind of a tight squeeze, it does fit through the doorways.
I was sad to put this away with my first daughter and I know I"ll be sad to pack it up again when my second daughter has outgrown it. Thank goodness for the Jumperoo!!