The beam shape of the Titan will need to be very compelling for me to invest in a AAA back-up light. My pocket light is a 1xAA Fenix E12 -- 8/50/130 lumens out, very useful output range.

The light on my keyring (DR Photon Freedom) is purely a back-up with the intent of momentary use to get me to a real light. After years on my keyring I finally replaced the battery after it was accidentally turned on and left on for an unknown time (I think the dog did it) but even then the light was good enough for its job of getting to a real light.

For the purposes mentioned in the article, lighting an alley or the woods at night, I would prefer to use a AA light for the runtime and commonality with my other non-keyring lights.

Might be a great light, but I'll need to see it first hand.