I got mine yesterday and I love it. I was also confused about the use of the Lithium batteries. So, I guess as long as they are just regular Lithium batteries they are fine, but if they are rechargeable that would make them Lith-ion and that would be bad correct? I will searching for the whole lithium information once I burn through the Rayovacs that I have.
I will also post some outside usage pics when it gets a few degrees warmer. But I walk my little pocket dogs last night. I tried the light for the first time in a wooded area I am used to my Fenix P2d, anyway I was really nervous that the D20 was going to be like a mini mag compared to P2D. But wow. I clicked the button and I was a happy camper. I love this little light so far. Mainly due to the size. I will get some pics and a short review here in a few days.