My honest review based on experience with both the Litter Genie and the Litter Champ.
For those of you who have cats and who have never tried either of these options, please know that either choice is a good one. They both beat scooping litter into individual bags and they're both better for the environment. They also will both greatly reduce/eliminate litter box smell. They're both basically like a "Diaper Genie" and in essence a dedicated garbage pail for kitty litter.
The Genie will cost you about $10 less and we were quite happy with it for about 2 years. It wasn't until we needed to replace it due to moving and not wanting to pack it, that we discovered the other option "Litter Champ".
So why do we love the Champ? Well for one thing, it has the step-on foot pedal which our Genie did not have. This is a great feature because it provides a hands off experience with the "Champ". When you step on the pedal, the lid opens just like a typical garbage pail with a pedal BUT it does not open directly to an open pail. Once the lid pops up, there is a plastic kind of "trap door" on hinges which is designed for a second layer of odor protection. When you place the droppings on this layer, the weight opens the trap door liner and the litter falls into the waste pail.
The Genie had a very different system. You open the lid and place the droppings and close the lid when you're done. They, you pull (what I refer to as the sliding trap door) which acts a second floor for the clumps and in theory, they fall to the bottom. This worked some of the time but not all the time and we would often find our selves maneuvering the Genie around in a way that would hopefully shake loose the clumps which were stuck towards the top.
Another great feature of the "Champ" is the child lock. I never thought this would be a concern until my cousin's kids started visiting and well, you just never know what they'll try get into! Gross, I know but thanks to the children's lock, we don't have to worry about it.
Again, we were very happy with the Genie and I'm certain there are many who don't feel the need to try something different. That said, we do prefer to Litter Champ and would highly recommend it.