At 6 months old, C is finally old enough to really enjoy his jumperoo! I love the jumperoo since it keeps him upright and lets him look around (since he's not sitting on his own quite yet). It's also nice for him to be able to entertain himself and stay in one spot while I wash dishes, cook dinner, etc.
We registered for this doorway jumper and received it as a baby shower gift; I love it in theory - a jumper that I can easily move around the house to the nearest doorway, and likewise can be put away easily when not in use. However, in reality, it isn't my favorite - it doesn't "bounce" very easily, and since there are no toys or other entertainment, C gets bored in it quickly - I'll look over and he's just sitting there still, staring at me (or crying to get out).
Better: Fisher Price Rainforest Jumperoo
Our pediatrician recommended getting a jumper of some kind to strengthen C's legs and keep him off his head (since right now tummy time is our only other option, and that doesn't work forever...). After our lackluster enthusiasm about the doorway jumper, I scoured my local Facebook online garage sale site and bought a Fisher Price Jumperoo. It is SO much better than the doorway jumper - it bounces easily, and there are several toys that C can play with if he doesn't feel like jumping. He will happily play in this for 30-45 minutes at a time.