This weekend I did a little runtime test with some 1AAA 5mm flashlights running them on IKEA Alkalisk batteries(1.79 Euro for 10).
Results as following from LED on to completely dark:

1. Varta/Rayovac Indestructable 1AAA: 43 hours (of which the last 36 hours really dim)
2. Sofirn C01 3200K (PROTOTYPE): 34 hours (approx. 20 hours of regulated output)
3. Sofirn C01 5600K (PROTOTYPE): 33 hours
4. Fenix E01: 26.5 hours
5. GP Discovery CLE202: 24 hours
6. Gerber Infinity Ultra task light: 7:15 hours (much lower than expected)

0. Control: Zebralight H53Fc on AAA alkaline: 45 hours on 3.5 lumen (lowest M). After that 5 more hours on highest Low. Then it started to flicker. When removed battery measured 0.85 Volts. Still good enough to light a Sofirn C01.

Edit 1: added prototype clarification
Edit 2: added Zebralight result