Thank you for taking the time to review the light for us, very much appreciated!
I just got mine in (actually two 
) and I noticed the strobe mode alternates in frequency every two seconds; a rapid strobe at 21.85Hz and a slower strobe at 12.14Hz. Might be useful to include this info in your review.
The two I got do differ slighly in output (there will always be sample variance) and the step-down timer is different as well. Here are some LBL numbers (lightbox lumens) with my two samples.
MT21A #1
Turbo - 276.1 (0s) / 249.6 (30s) / 201.7 (142s) LBL
High - 124.4 (30s) LBL
Med - 57 (30s) LBL
Low - 9.3 (30s) LBL
MT21A #2
Turbo - 239.2 (0s) / 217.6 (30s) / 176.7 (148s) LBL
High - 122.6 (30s) LBL
Med - 68.9 (30s) LBL
Low - 14 (30s) LBL
Overall in the end I’m pleasantly suprised by this light. Good output and great throw for the 2 X AA format. I wish there was a stainless steel bezel to protect the lens, but for the price I paid I really can’t complain at all.