I received mine today. My quick initial impressions is that it's very compact to hold. The UI may be something to get used to in that you have to hold it like you're throwing a mini football with your thumb at the bottom to actuate it one handed. I'm also noticing a bit of an outer corona with extending "flower petals" at the outer most edges. BTW, these are white wall observances in my house so you probably wouldn't notice it outside. Also, the tint on mine is much warmer when compared to my 3800 TM26. I'd much prefer the one button interface like it is on the TM26. Overall I really like it despite these minor points. I have another one pre-ordered so I look forward to that one when it comes in. These online discounts are so irresistible!
So if the Niwalker MM15 is the soda can flashlight then the Nitecore TM06 is the slimmer "Monster / Red Bull" version.
I also received the Olight SR Mini. This one outputs a pure floody beam. The pattern on it is smooth in comparison. It's not "busy" in comparison but not as penetrating as the TM06. It has a cooler white temperature that I much prefer. However, I find it a bit odd double clicking to get to the next level.
Overall I love the variety that these lights have. Now it's time to get take these babies outside for a spin!