Before I started using the Cera I put a meter on the atomizer and it started at 2.0 ohms then fluctuated between 1.8 and 1.6 ohms. The battery was 4.15 volts so everything looked good. TET says the atomizer takes a little time to break in so that was the plan. They also say you have to depress the switch then wait about 5 seconds before the atomizer starts producing vapor. Thats different but OK, here goes. The spring on the switch is not difficult for me but my hand strength and coordination is good. While I have no problem operating it with one hand the switch could be a problem for someone with weaker hands, especially if you have to hold it down for 5 seconds before it starts to produce vapor. As much as I hate to say it, the device does not produce the amount of vapor it should. Dont misunderstand, it does produce vapor but I figure if a person is going to spend big bucks on a device it should perform better than just OK. Although the atomizer seems to get plenty hot enough, there just isnt much vapor flowing through the mouthpiece. I removed the mouthpiece and stuck a Tru-Flow drip tip in the atomizer but I still didnt get much vapor. The only time I really got a good amount of vapor is when the atomizer was almost dry. That vapor was really hot and burned the hell out of my throat. It put a whole new definition to throat hit! As soon as I put a drop of liquid back in the vapor production decreased. Its like the atomizer is flooded with only one drop. When I remove the atomizer cover I can see the liquid bubbling and I can hear it sizzling but it just isnt vaporizing. I was patient hoping that it just needed some break in time but after playing with it for a few days its still not getting any better. The 2900 mAh battery went dead so I put it on the charger. Its the only 18650 battery I have so I put a 17670 battery in it and it worked the same as the 18650. After the 17670 battery went dead I removed it and put in a pair of AW RCR123A LiFePO4 3.2v batteries. I wasnt sure if they would burn up the atomizer but I decided to give it a try. It didnt burn up the atomizer but the atomizer did get much hotter. Unfortunately it still didnt produce any more vapor. Strange! I put the fully charged 18650 battery back in it and it works about the same as it did. It appears the atomizer will work with both 3.7 and 6 volt batteries. I dont know if using 6 volt batteries will void the 1 year warranty on the atomizer but it doesnt really matter because Im putting my Cera on the back burner for now. I have a contact at TET that was not a part of Apex Vapor and he replies to my emails. He told me they are working on a reservoir system that should increase the vapor production and provide a good liquid delivery system too. He says it will be available in a few weeks. Ill be back, I hope.