Ok, got the 123 light, XTAR WK42, a few minutes ago out of the mail box. First thought was the same as when I got the Olight S10 Baton...wow tiny.
Led appears perfectly centered.
The clip contacts the head so you must hold it away while screwing the light apart...and back together or risk scratching. Also the clip is not reversible...so no go for a quick baseball cap head lamp.
Threads are not square...would be my preference.
Put a Eagletac batt in there I ordered with it and turned it on...to turn it off you must press and hold for a few moments...I find this a bit irritating as I am used to a quick click...so I tend to bump it to the next power setting before remembering the press and hold concept. Might get used to it over time. Switch itself is soft, comfortable and has a nice little click to it.
Anodising looks to be flawless...knurling is good, feels good....nice grip, without being a file in the pocket.
To bright around here to make comments on brightness, beam quality, tint...will later tonight. Maybe a high mode run time test...to low batt warning light first turn on. At which time it will be switched to the 30 lumen setting and continued till warning light begins to flash, to mimic a real world "oh poop" experience.
Battery is charging now.