Niuniu @40 - 40% Low Profile Mechanical Keyboard Kit

Its great. I an typing on it right now. Very silent and sturdy,

I'm an illustrator, who normally daily drives a TKL with Numpad at home and a Full-Size at my office job, but this is my second keyboard on the smaller side and first ortholinear.

Size Feel (subjective) – 5/5

My first small board was a 65% but it felt too awkward to use at times, because even though it's on the smaller side, it still a tad too big for my small hands. (And it had very bad software and customizability, but that's besides the point.)
In addition to that, there was a lot more unnecessary arm movement caused by the pre-configured keymap and higher key row count.
So this 40% size is a lot more compatible with my hand size and there is much less arm movement required.

Ergonomics – 4/5

Besides the key columns and rows being linear, you are even more inclined to keep your fingers on the home row now – This means that people who's fingers don't all end in one straight line, which is most people, will probably find the use over a few hours to be exhausting on the fingers.
It is a general problem with the layout and not this keyboard specifically – you'll just need to try it out and see if it fits your needs and preferences.
(The issue is partly amplified by the non-split, non-column staggered layout, which is not very ergonomic, but I don't constantly have both hands on the keyboard, so I'm okay with that.)

Portability – 5/5

The small form factor (236mm*85mm*30mm) and low weight (~550g) also makes it easy to put into a backpack, together with a laptop, water bottle, etc. and not suffer from a cave man gamer pose.
(Though I am a little sad it did not come with a carrying case like previous keyboards by Niuniu… But an extra like that is not always a given.)

Software – 5/5

Also the first time I used VIAL to configure a keymap, but it's really easy to switch to, coming from VIA. (I'm a VIAL believer now.)

Switches and Keycaps Feel – 4/5

I bundled my @40 with Kailh White Rain switches and LCK Reverse keycaps.
The switches make a pleasant muted, deep sound. The slight resonance inside the aluminium case and the carbon fiber plate compliment it giving the overall sound more life. (I chose them over the Reds and the Spring switches because I prefer a heavier spring.)
The keycaps are quite packed in terms of legends, but if you are more of a "function over form" person in this case, go for LCK Reverse!
(Note that you are not restricted to configuring your keymap in accordance to what's on the keycaps, but it definitely helps to learn in order to get used to it.)
The convex shape of the space bar keys, in contrast to all the other keys that have a concave shape, give the impression that they are much higher than the rest. Don't be like me and use a 1u spacebar key as a layer mod key. It'll fatigue your pinkies. Ouch :(
Can't say much about the quality, sinceI have no clue about that lol, bit they seem crisp and clear.

Building Experience – 4/5

The building experience was pretty short, easy and simple for someone experienced, though a short building video guide or 1-page manual would be very helpful for beginners, especially considering the keyboard doesn't come pre-configured with any keymap.
Stabilizers and switches came pre-lubed, no lubing required, magnetic connector speeds up the building process by a minute or five. (But the tube in which my switches were stored in did smell fishy, even after washing it with soap…)

TOTAL – 4.5/5

Overall, (speaking with very limited experience with 40%s,) the @40 is a really great keyboard for a mobile work setup, if you mainly use it for keyboard shortcuts and moderate amounts of typing. The tri-mode compatibility helps a lot if you use many devices with this keyboard.
Even though you can configure the keymap to whatever you want, I honestly would not recommend it for gaming – but that's up to you. If you can help it, I'd go for a bigger keyboard size or controller. :)

Thanks for reading. Have a nice day!