I am a huge fan of products made by Native Instruments. I bought their stuff since 2008, mainly software instruments (VST). Since they also make hardware such as keyboards and other MIDI controllers, I also had my hands on those.
The first controller was the Maschine Mikro mk3, the little brother of the famous Maschine controller.
This thing is amazing, the workflow is flawless using the Maschine software and it is still in use. I also have a Komplete M32 controller for traveling, a 32 key mini-key keyboard controller with all the integration to Native Instrument's software eco-system.
The final piece of gear was the Komplete A61 which was planned to replaced my Yamaha DGX-630 E-Piano which stopped working on newer macOS versions some years ago.
Fortunately Yamaha updated their drivers (yes, you need those for some reason) last year so it now works again - but I didn't know that.
The A61 always felt a bit cheap, the keybed was too soft for my taste. The housing is plastic and playing it produced a lot of clonky noises. I appreciated the wooden weighted hammer action keys of the Yamaha (like in a piano) which the A61 never replaced.
With the Yamaha not working for me for a while and the A61 not feeling good for me, I searched a replacement and I sold it. I found it in the Arturia Keylab 88 mk2.
With Native Instruments being a Germany (Berlin) based company I now got this beast of a controller from France. The keybed of the Keylab 88 mk2 is a Fatar TP100LR which is a premium weighted hammer action keybed made in Italy. It's a bit heavy but you can get used to it very fast. The housing is metal and built like a tank. It weighs 15kg - remember, this is just a controller, it does not produce any sound on its own.
The real benefit also is the DAW integration. The NI never worked well with Logic Pro X which I use. The Arturia does better. It comes with a DAW integration for most of the popular DAWs including the challenging Ableton Live. Actually I am using it here and there since I have it because it's so easy.
The knobs and faders feel pretty premium but the killer is the main control encoder wheel and the buttons around. It is designed to control the included software instruments Analog Lab V, Piano V, Wurli V and Vox Continental. Overall you get more than 6500 patches of famous synths, organs and keyboards from the past 40 decades - there is also a Mellotron! An awesome collection!
The DAW integration with Logic in my case makes me forget to use the computer. I don't have to grab the mouse or look at the screen anymore, just playing and recording, undo-ing, repeating etc. This is what I missed with the NI controllers so much as they focus on Ableton Live primarily.
After about a month with the 88 key controller I was looking for a smaller one for my other smaller workspace. I came up with another one from the Arturia Keylab family, the Keylab 49 mk2 which I bought as a used device from eBay.
This one is also in a metal housing, the keybed is the one from Arturia's premium synth MatrixBrute and feels really good. It's very easy to play, feels smooth and does not produce a lot of noise. The rest of controls it is identical to the big guy, so I have a continuous workflow now.
Actually, I really love the NI software instruments but hardware-wise I would definitely recommend Arturia as the best hardware in this price range. The Analog Lab V VST is also one of the best VST I've ever used - hands down.