^^ Nice fair comparison/evaluation.
Wouldn’t make sense to run them side by side at max, esp. on 14500s. The SC52 has the 1min stepdown and better heat dissipation, while the D25A would probably scream until it caught fire. I ran a 2012 D25A Ti NW XML side-by-side with the SC52 on Eneloops on high though, particularly since they match-up as the same on my light meter. On High, SC52: Specs: 108 lms/ 3:00 hrs Tested: 80>40lms/ 2:28 ET, D25A-XML, NW: Specs: 75 lms/ 2:30 hrs Tested: 80>40lms/ 2:20 Note: both lights exhibited similar drop down performance. Solid regulation throughout test, before dropping off quickly at the end. Efficiency equal.