I am an engineer and over analyze everything. When we had our first child, I was the new dad that dreaded poop. Luckily I have overcome that fear. However, we had several different "stink-free" cans and I threw all the others in the trash. The other brands just suck. We had this one brand where the circular lid slides along the horizontal plane of the lid...when it was nearing full, the diapers would essentially hit the d*** lid and smear poop on the backside, putting poop where it can't physically be cleaned. This sucker though, well thought out, easy to change the bag. I highly recommend the version with the step to open. The other one with the manual lid is a bit shorter and when you get poop everywhere, you will need to open the lid with your poopy hands, thus getting poop on the lid.
ALSO, if you subscribe to the bags on Amazon, its by far the cheapest you will be able to find them. I have found that a box of 20 will last us about a 2 months - kids are at day care, so most of the filling happens on the weekends. I have no preference between the donut bags and the preformed bags with the plastic clip, though I think the donut bags might be cheaper. I enjoy the convenience of the preformed bags and I'm too lazy to figure out how to change my Amazon subscription.
This sucker significantly reduces the stink. Remember, there is little way to totally eliminate it the stink, but this is by far the best I have experienced and it is dang close to eliminating it completely. If you are a parent to be, this is your diaper can. If you don't buy this, then just buy a regular old trash can with the step to open feature and save your money. Do not buy any of the other pricey diaper pails!