Borrowed a friends [6 month old] X65 for a week and liked it so much I ordered one. After it arrived I decided to run a few tests against the TN40S NW, which has been our daily user. All three of our TN40's test the same, so we grabbed one to see how it would compare to the X65's. These were simple ceiling bounce tests done at 4, 6, 8 and 10 feet. His was consistently 2.45 times brighter than the TN40, while the new one was consistently 2.80 times brighter. The two X65's head to head produced nearly the exact same results. We also swapped the battery packs, but the results didn't change. Assuming the TN40S NW is 4,005 lumens (90% of the 4,450 CW), that would mean: Old = 9,812 New = 11,214 The difference of 1,400 lumens (nearly 15%) isn't huge, but definitely significant. When using both lights outside the beam patterns and temperature looked identical, one was just brighter. This was nothing scientific of course, but interesting nonetheless. Do you think it's simply a light to light variation, or did Acebeam change something with the newest X65's?