One major advantage of The Diaper Champ over The Diaper Genie is that it doesn't require any special bags. With The Diaper Champ, you can use *any* type of plastic bag (tall kitchen trash bags work great), but with The Diaper Genie, you must use its specific type of bags. The Champ is also easier to use than the traditional Genie because it doesn't involve the twisting mechanism.

That is one big advantage that the Diaper Genie II has. It is easier to use than the original because you skip the twisting step. Just lift the lid, insert a twisted diaper, and close the lid. It's also able to be opened and closed one-handed, which is a great feature. On the downside, it still requires refill cartridges (like the original) and it is more expensive.

Between the Champ and the Genie, I would certainly go with the Champ. It is less expensive, less complicated, and contains odors just as well.

If you're interested in another option, check out Diaper Dèkor. It contains odors very well and is also easy use one-handedly. The Dèkor also has biodegradable refills.
http://www.diaperdekor.com/

My wife and I had a Diaper Genie when our first child was born. We threw it out after about 2 weeks and just used the plastic bags we got at the grocery store. If you really want one use the one that uses garbage bags. the diaper Genie special bags are expensive.