So I got the M91T and traded M61HOT.
The MD2 "HOT" is a neat module. It was the smallest-most powerful light I had. Truly a pocket rocket. The other way to put it, it had the best size efficiency I've ever seen. Now the Hound Dog Super MD6 I have is a lot brighter but it's also 3 times bigger. The regular HD is also much brighter but it's also much bigger. This thing is relatively tiny and throws like a <insert your favorite term here>
Yet much as I tried to like HOT I never did love it all that much.
It had a very high almost 2Amps consumption, I think the exact figure is 1.75Amps. and yes I do know most of the local expert do not think it's high at all. Well.. It's high enough that 123s are not recommended. They can but not desired. Didn't run on anything but 18650. The runtime wasn't that good. It did not run on all the 18650 cells I had. I had a lot of older 10 year old junk cells and some of them didn't last very long at all. I did get the stated 30 mins on new 18650s that were high capacity.
So there it is, the M91T. I don't have the M61HOT to compare it with anymore but I got the impression that the HOT threw a bit more, had a bit hotter hotspot. Indeed, comparing the lux numbers, HOT is 20K and M91T is 19K - very close. Now the total lumens goes to M91T and the size of the hotspot is larger. It's truly an impressive wall of light. It's bright, the hotspot is nice and huge and it destroys the M61T that I have and laughs at the M61 so bad it's not even funny.
the module really shines on 2x18650 -- you get the lumens, the runtime *and* if you so desire, can stick in the common 123 cells in it if you run out of precious 18650s. Now that is something.
I think 2x18650 with the M91T is the largest EDC you can even contemplate. I have some nice cargo pants where it disappears. The smaller 18650 HD is kinda too large to fit in all pockets, due to the diameter but this thing is slim.
Of course the 18650 HD destroyed the M91T, as expected. Not lumens wise but the lux is much higher in HD, they are completely different lights and I do recommend both as a matter of fact.
Now the lumens difference between HOT and M91T is minimal, only about 75 lumens. It's actually hard to tell. It's there but only a hair.
The real difference is the runtime. And the ability to run multiple cells that's the winner here.
I don't disparage HOT at all, if you want a subcompact with tons of lumens, this is it. It was and still is a rocket. and well worth the coin.
The other good thing is, the M91T generates 30 lumens on low, much more useful than the 7 lumens on low that HOT generates.
Everything Malkoff makes is great.
Now if you want smallest possible package with most lumens for EDC, M61HOT is it.
If you want variety and the ability to try various combinations (2x18650, 4x123, and MD2 with 2x18350s, etc. etc.) M91T is for you. The lumens level is approximately the same. 575 lumens vs 650, HOT and M91T respectively.
Basically out of M61T, M61HOT and M91T, pick 2 out of 3. They are so similar that not sure all 3 are needed.
I picked M91T and M61T but could very well live without M61T with HOT instead.