The atomizer in the eGo/clearo rig I use is 1.5 ohms. The juices or mix of juices that I vape are on the clearer/non particulate side of the spectrum, and I vape not that often/much. The atty is stated to last 2-3 weeks, but I'm on close to 2 months now and I think it's working just fine. When you notice that the vapes just aren't as 'vapey' anymore, even with a fresh battery, it's time to put in a new atty. A statement such as "this atomizer will last this long" just can't be made, because everybody has different 'vape preferences/standards'.