I didn't have a jumperoo, but when I worked in daycare we had several exersaucers so I bought one for my baby when she was little. I also bought a jumper you hang from a doorway. Unfortunately we moved to a place that had no doorjams and so I really wanted a jumperoo!
I read the 3 star reviews for the Precious Planet Jumperoo on Amazon and they said it's very big and heavy so once you get it together it is NOT very portable. Well, my hanging jumper went with us everywhere- friend's house, out of town, grandma's house ect. It was very portable. We also took the exersaucer with us as we could collapse it and slide it under the seats or put it in the trunk. Moving it (or the hanging jumper) from room to room was easy too, so I could take baby to whatever room I was cleaning. A HUGE plus.
Also, my babies didn't like jumping so much as they liked swinging in the jumper. They would jump and put their feet up and swing and twirl in it- they can't do that in the jumperoo. I don't think my kids would have liked it as much. And the exersaucer they can walk around in circles. They DO jump a bit in the exersaucer.
Conclusion- get the saucer AND buy a door hanging jumper from a resale shop, garage sale, borrow it or buy it new but if you have door jams they are fantastic. Our new home has them and I used my jumper with 4 kiddos and they all loved it. I have used three different kinds and the ones with a tray are my favorite- the act as a bumper when the baby is very wild and you can put snack on it and they will sit there and it their cheerios (make sure you always keep an eye on an eating baby, though.)
S.