Everybody’s skeptical of the claim of 2500 lumens OTF from a single XHP35 HI, especially using a single Li-ion battery. Texas Ace barely topped that running it from a bench power supply with no optics.
Vinh tests the stuff he sells and reports what his equipment reads. I don’t know what his test setup is, but I expect his numbers are somewhere near reality.
None of the single-18650 XHP35 lights I’ve tested have actually hit their numbers. Acebeam came closest with the L16 (claimed 2000lm, measured 1700lm for a 15% difference).