using proprietary battery is a nay.
Oops…
Proprietary batteries (even worse if magnetic charging is involved), no support for NiMH batteries, cold white emitter, electronic switch => basically, Olight is a dead brand to me.
Too bad, because they make gorgous models. Also my one Olight 1*AA (discontinued) was pretty nice, but flawed due to the above.
Also shitty PWM (no PWM is best), any mode other than (ML)/L/M/H, next mode memory (who the hell even invented that ???), momentary switch.
true but frequently you do not realize that til later
price is important - i will tolerate more flaws for less money
Excessive bulk, knurling, and anti-roll features aggravate me.
These might be more useful if I used my lights for tactical purposes though.
I don’t like on board charging either. I’d rather have more reliability with one less system and remove the most likely place of water ingress
Long timeouts. Don’t mind if it’s hold for off or hold for next mode, but I dislike if the light lets me wait forever (i.e. longer than 0.5s).
Mode memory without shortcut to moon or low.
Bidirectional clips.
No shortcut to moonlight and turbo modes. One of the only issues I have with Convoy lights
Dimness.
Blinkies.
Awkward body/UI.
Momentary OFF switches.
Non-white beams, especially with rainbows (CRI).
Unregulated battery consumption.
Spendy, despite the above.
When I turn my lights on, I expect them to return the favor.
Proprietary batteries or non replaceable batteries.
I am not buying something that’s potentially useless a couple of year down the line as it’s batteries shot and I can’t replace it.
I won’t even consider buying a light like that.
Are you listening Olight?
Olight listens to the variation game, akin to CASIO with their G-Shocks (insane how many color and style variations they make on a single model).
Cold/low CRI emitters.
365nm UV lights with no ZWB2 filter.
1x (whatever cell) tube light with designed-in Inability tailstand.
slmjim
Yeah, Casio knows what they're doing.
I have a favorite Casio watch, and it's available in maybe four different color varieties.
(I still need another of my favorite color variety.) 
All of the above and adding to that, low mode that starts at 50lm or higher. What’s with that? I live in the city, not in the jungle.
The most unacceptable thing about flashlights for me are the custom-made, high-end titanium lights that I can't have.
Non-replaceable/removable batteries.
mushy switches
CASIO knows how to milk the masses… There’s just so many buyers who aren’t very discriminating, so CASIO isn’t motivated to make a number of improvements like they used to do. A handful of years ago, they took suggestions to heart from the CASIO owner forum and it was great to see improvements gradually introduced. But they’ve stopped doing that. Now it’s all about adding metal and bumping up prices, massively so.
Still, despite all of these years where tech improvements can be made, so many models have anemic alarm tones. I still have some CASIO G-Shock watch models from around the start of the 21st century, and they have reasonably loud alarm tones. But today, it's nearly impossible to find one that will be loud enough to overcome even mild room noise. Thankfully they did re-introduce vibe alarm... something I rely upon a lot.
But as this is a flashlight forum, OLIGHT should try to be more mindful of the flashlight community.
I have an S1 in Titanium, with a reasonably neutral LED and a nice moonlight mode. But still, they're so often introducing flashlights with lack of good moonlight and tints that are too cold. I'm still waiting for a neutral LED in the i1R2 EOS.
I agree with the OP, and I have a hard time buying anything without a SS bezel ring. It can’t be that hard to, I have a Superfire that has a nice SS ring for pete’s sake!