The main reason we chose this one over any of the others was the lack-of-budget that limits so many people. This controller is cheap - REALLY cheap.
For that small price, however, you get basically EVERYTHING you might need to create music in DAWs like Ableton and FL. That makes this machine a "tiny wonder".
Now that we've been using it for a couple of days we've found that it does exactly what you would expect of a controller. It works, straight out-of-the-box. It is immediately recognized by the various DAWs we use here (mainly Ableton & FL).
The keys, albeit small, feel pretty responsive and are easy to play when you want to add chords or a melody. The buttons for pitch-bend & modulation actually work very easily. We have full-sized keyboards here with wheels, but these buttons are surprisingly responsive and do the job perfectly. The size they save on your desk over a wheel is definitely worth it.
The pads take a bit of getting used to as they do have a slight tendency to "double-trigger" upon release. Once you get used to playing them, this goes away.
The knobs feel a bit tighter than I would personally like as my fingers have a small tendency to slip on them. My fingers are good for playing pool, it seems, but not so much for turning these knobs. However, my partner doesn't have any problems with them. YMMV, I guess.
Our choice would have been between the V mini or the V25. The V25 has bigger keys and more pads & knobs. It is also 1.5x the price and it wouldn't have added anything that we needed and is also bigger, meaning it would have taken up more space on our desk (that we don't have).
Overall: Thumbs up! Very satisfied with Alesis for creating this fantastic controller.