Well... It's seriously impressive for the size. The throw is just fantastic as is the output for the 10180 battery. On the original battery it only maintains turbo for about 15 seconds. Other brand 10180 cells only hold it for 5 or 6 seconds so I think the original cell is a high drain type. My one arrived without the button backlight working and I've heard of other cases where it either doesn't work or is VERY dim so that seems to be a weak point. Even if it did work I'd have turned it off anyway so I'm not bothered. Other than the backlight, the quality seems to be quite good.
If you keep it down to 110-150 lumen output the battery lasts long enough to be useable but let's be honest, you aren't going to be going caving with it.
We all have a bunch of other lights so here is the actual bit that matters... it just 'feels' fantastic. The whole tactile feel of the thing is so good. Something about having a micro size thrower you can roll around between your thumb and two fingers is just really nice and occasionally you double click to turbo and giggle at the sheer output and throw. You all know I'm a bit of a micro light collector and this by far is my fave to actually hold and play with. It's like you had a huge thrower and put it into a shrinking machine.
If you want to make it a bit more useable you can get an extended body so it will fit a 10440 cell though I found that many of my aaa light bodies fitted fine. The Thrunite Ti3 body is the best match but the proper body is only 6 dollars.
I got mine on pre-order from Banggood for £18. Now you don't seem to be able to get it for less than £30 or so which is a bit steep. I probably wouldn't have paid that.
On the other hand... I may pay that now if I lost this one, now I know how much I like it.