Although I am a guitarist/singer, I wanted an affordable midi keyboard specifically for editing. Taking into consideration the good price and positive reviews, I chose the lpk25 and I truly do not regret it. I am currently using it with reaper and various VSTs without any problems whatsoever (I have read reviews that claim it works flawlessly with most popular DAWs). My computer (Windows 10) automatically recognized it without needing to find drivers, and I had no trouble locating it in reaper, I just had to select it as "active" in the settings. I don't have much experience to compare it to other similar models, but I am completely satisfied with the sensitivity of its keys, the sustain button on the left side, and the easy octave change, making it very practical even with just 25 keys (the functions I mentioned also work plug n play). It comes with a CD which I didn't need to use, but I imagine it contains a program for additional parameter adjustments. Its size is truly laptop-sized, so it can be easily transported anywhere without needing extra cases. Lastly, I am impressed with its build quality and I will definitely trust Akai again in the future for a larger-sized midi keyboard.

It is very small and very lightweight, it has a length like a 15' laptop and fits in this bag, it doesn't need power, it doesn't need drivers.
It has an arpeggiator with many options and 4 memories, tap tempo, sustain button, octave -+ button.
In the video, the guy shows how it works to give you an idea, https://www.youtube.com/watch?v=PtGjriY2_5Y
For its price, I don't think you can add anything to it.