Heck, I'm at 9 months on one of 18650s. Of course, I've recharged it a few times.Making a nonsensical statement and not backing it up with any proof or reasoning is worth exactly zero. I could claim I get a month of use out of a single 18650 and it would be meaningless unless I provide some kind of hard data.
Titanium allows more "conventional" builds than nickel does. You can use thicker wire and you don't need lots of wraps or a huge ID to keep the resistance reasonable. Is it possible that such builds are more efficient? Honestly, I don't know, I'm just speculating. I gave up on nickel within a few days of getting my first DNA40 back in October. I decided to try titanium because I already had it laying around from previous experiments with it, and quickly concluded that it had none of the drawbacks of nickel. I only see one downside to it and that's the fact that the DNA40 isn't "calibrated" for it; you need to set the temperature limit lower than the temperature you really want.