Yup, his TK41 video is what had me second guessing buying the M3X. I had both videos side by side and I couldn't really distinguish a difference between the two.
Sorry it took me so long to get back to you on this one. I didn't see your post until today.
This is my comparison and thoughts of the TK41 and the M3X.
M3X is lighter weight and easier to carry. It also comes with a holster.
The M3X throws a little better than the TK41 but not by much. In real world usefulness, there is not enough difference in the throw to make any difference. Both throw farther than I'm likely to ever use or need in the real world. The WOW factor with both lights is very high.
The TK41 was $10 less expensive but again, you get a holster with the M3X. Your mileage may vary depending on where you buy it.
I like the forward mounted buttons on the TK41 better. You can change modes with one hand. UI is great. On the M3X the UI is very simple because it only has 2 modes but it takes 2 hands to change modes. The low mode on the M3X is nothing special and I have other lights I would end up using instead of using the M3X on low mode. The high mode on the M3X is what sets this light apart and the reason for owning it in the first place. Throw Baby, Throw!
The hot spot on the M3X is very clean. It's not quite as clean on the TK41. M3X hot spot is also a little smaller.
Both lights tail stand but it's easier on the TK41.
TK41 has a little more spill and it is a little brighter in the room when using ceiling bounce.
I can burn the M3X longer on one battery charge on the highest mode than I can on the TK41. Your mileage may vary depending on which batteries you are using. I have not been able to get the battery run time in the TK41 that is listed on their spec page. The longest burn time I have been able to get out of 8 AA NiMh batteries was about 1 hour and 50 minutes using Powerex 2700 batteries. I get about 10 minutes less using eneloop 2000 batteries. I can get about 2 hours and 15 minutes out of the M3X on high using two 18650 AW, Callie Kustoms or Redilast 2900 or 3100 batteries.
However, on the TK41 battery run time is so good on the other 3 modes, it makes up the difference. I find all four lighting modes very useful on the TK41. I am shocked at how far the TK41 throws on it's 10 lumen low mode.
If you're using your light only for throw, the M3X is the one for you but not by very much. I find the TK41 to be much more versatile and usable because of the extra modes. The fact that it uses AA NiMh batteries is frosting on the cake. Even though I have lights I use more, still the TK41 is my favorite flashlight.
BTW: The TK41 has one of the best finishes of any of my lights. The threads are as good or better than any of my lights.
Just two small complaints I have for the TK41. I just wish it had a holster as it's too big to put easily in a pocket.
The battery pack rattles a little inside the body of the light. It's a simple fix. I just wrapped a 3x5 index card around the battery pack and it's Problem Solved.