I think REI pulled some of those numbers out of their butts on that specs page. For one, the Petzl e+LITE uses the Lithium coin-cell batteries which perform better in colder weather than standard alkaline, which the Tikka Plus is limited to. Secondly, the advertised specs on the e+LITE claim 45 hours [citation] as the burn time in economy (low?) mode. Whatever REI was smoking when they wrote that page, they need to pass it to the left, or maybe try writing the specs out when using fresh batteries.