for my MCU-C88 with U2 1C XML (modded by E1320 - Erik) so that my wife does not freak out about me spending money right before Xmas, LOL. Reached my limit for a while. Going to use alkalines in the C88, probably until after the holidays.
I have a KD SST90 driver, and it's closer to 6.5A than 9A. It requires 2-cells as well.
If this 26650 torch has a single driver pushing 3 XM-Ls, then it's a new boost driver that we've been waiting for. I'm skeptical, but hopeful that that's the case.
I have ordered one, hope only, that it finds out how many cells are connected, that KAI didn't put constant cell protection on 5.7V and we will not be able to use it with one cell despite it can work like this. And second thing is size, but that may be solved on host already.
Don't forget that the S1 and TM11 accept 4.2V input for at least 2000 lumens. But those cost much more of course so definitely more design and engineering goes into their driver.
With KingKongs for example you know that you get over 4000mAh even on a 10A discharge. So, yes you get better runtimes and the cells can deliver high currents if you need that now or in the future. For the price you can almost say that you have 2 x 18650 cells in one.
What charger do you have, any charger can charge 26650 cells with you use some wires and a couple of magnets.