Lithium may be more $ but they tend to last much much longer than alkaline.

Night vision recovers quite quickly unless you are shining the light directly in your eye. Ouch!

The collar on the Photon helps with the side scatter so that you illuminate what you need. I haven't found that my night vision degraded when using it, turning it off, and looking around. As stated, your eyes tend to come back quickly unless they were exposed to bright light then dark.

YMMV.