I got one of the new TINI 3's when Nitecore had it on sale for $29.
The things I like are all objectively good; the things I don't like are matters of taste for me, so maybe you will like them:
Good things:
Increased turbo from 500 to 600
Increased runtime on 1 lumen from 60 hours to 85 hours. Awesome! an additional 25 hours.
Increased battery capacity from 280mah to 330mah
Bad things:
Lost "demo" mode. I liked having this as a secondary lock-out -- if an accidental button-press somehow overrides the standard lock-out, then at least the demo mode will shut it down in 30 seconds.
Added diffuser to front lens. The TINI2 had much more of a hotspot. Now the TINI3 has a diffuse blob. Me no like. But I realize this is a matter of taste.
Meh things:
The temperature-switching (cool, neutral, warm) is a gimmick in my view. The CRI on this is fairly poor, like mid-60s. If they wanted to put in a fancy emitter, I would much rather have a really hi CRI number than the ability to switch temperatures. Yes, I have aesthetic preferences for color temperatures. But I would rather have 95 CRI at any temperature. This is a "meh" issue both because I know many people will feel just the other way, and because I don't think the CRI on the TINI2 was any better, so this is not a step backwards for the TINI 3.
The shape is slightly different, not better not worse. The TINI2 is a slab-sided box; the TINI3 has angled sides but is slightly thicker. The floor-plan of both is about identical, though the TINI3 grew trivially (length: 1.83 > 1.86; width 0.98 > 1.00). It is still a tiny light, no bigger than the last joint on my thumb. If you want a more streamlined shape, the TINI3 is better; if you want to pack it into a box, the TINI2 is better.
Overall, it's an amazing tiny light. Ridiculous output or amazing runtime, from a light the size of a postage-stamp. Recharges on USB-C, or runs while recharging. I wish they had not put a diffuser pattern on the TIR lens, and I wish they had kept the "demo" mode as an option. But otherwise, good improvements.