Sofirn UI have always been better than the competition. My personal favorite is a well done ramping UI like that of the D4 and Narsil. Cant Sofirn just ise Narsil? Isnt it free to use? Its tweakable too to accomodate everyome’s different preferences.
It is free to use, but since it is open source, you have to contribute back with your changes to NarsilM in exchange for using it.
Also, the problem is you have to buy a capable micro controller, which is more expensive than what most Chinese manufacturers use usually.
The way I see a good UI for any light, it needs to have 3 basic modes that can be accessed from off with 1 more of the users choice in the middle. That to me is what makes Tom E’s Narsil so great for me.
From off you have moonlight if you hold about a half second, from off quick tap starts in last mode used in memory which I set as low, Double quick tap starts in turbo from off, click and hold from off gives you ramping to select any brightness level you need. Memory doesn’t work with turbo or moonlight because you already have short cuts from off for them.
So from off you have Moonlight, Low (or set memory level), Turbo, and Ramping all depending on the time of the first click or double click.
Narsil has many other nice features, but to me this makes the UI so darn good. From just one click any brightness level is accessible and one fast click to off.
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Tom E has done a outstanding job with Narsil. I’m so very thankful that he has shared his hard work with the rest of this community.
He has set the UI bar so high, everyone else is struggling to keep up. Hence the question in the title of this thread.
Its all about the simple one button press to get the perfect amount of light and one fast click to off. 
But since NarsilM is regarded as the best single button flashlight UI by the majority of the flashlight community, it’s worth adding a few buck to have the best. For example, once TA came in to rescue Haikelite MT09R with his driver using NarsilM, everyone was singing praises of how well it works.
oh wow i didnt know Tom E was the creator of Narsil.
Yes the UI is smart and no doubt Tom is the brainy man behind the firmware. YES im hooked to Narsil and converted most of my lights with his firmware
It meet all my needs for moon/turbo/ramping from start.
Option 4, Olight style.
I should have included that option… I do like their basic UI>
USB cable has two purposes: to keep costs down and increase reliability.
If you can not use the UI programming program you have at least two ways: the first is to buy any other torch that the market offers; even if he will never have the torch to which he has given the characteristics he wants (and which can vary at any moment); the second way is to learn how to use a simple PC or MAC program.
The programmable flashlight will however attract the attention that in the commercial field means free advertising.
A few years ago a Bluetooth flashlight was built https://www.fasttech.com/product/1342000-flex-asgard-1052-lumen-programmable-cree-xm-l2, but it had both technical problems ( implement Bluetooth is harder than usb cable) and marketing