I bought this mainly on the basis of Nick Magnus's review in Sound on Sound (November 2017), and I'm very pleased with it. If you're looking for something with a good[1] action for a reasonable price - and you don't need lots of bells and whistles - I think it's a great choice.
[1] ...rather than "superb"; read on.
It's definitely five stars for quality: it's _very_ well made, as others have noted; the standard of construction seems extremely high. I've only had it for a week - so time will tell - but I expect it to last for a long time.
I love the appearance. I think the simplicity is very elegant, and I like the way the pitch and modulation wheel glow red (it's a slightly muted effect, but it looks quite striking in late night sessions).
I deducted a point for features. Not for the absence of pads and knobs, because I wasn't looking for them (if that's what you need, try the "Pro" version). And not for absence of an on/off (power) button; I don't care about that. I gave it four stars rather than five because it doesn't have a "graduated" action (i.e. the resistance and response of the keys don't change as you move from the lower to the higher octaves). This would have increased realism, but it would also have increased the price. The "Pro" version _does_ have a graduated action...but it also has lots of controllers I don't need (which makes it look cluttered); I decided it wasn't worth the extra money.
Notes for Linux users:
* This is a class-compliant device, so you don't need drivers.
* Many parameters can only be altered using the controller app, which isn't available for Linux: it's Windows (Windows 7 or later) and macOS only. But the Windows version (v1.0.8) seems to work in Wine (albeit with a few slight glitches in the GUI: some of the labels for the controls don't render properly). I haven't actually needed it, though: the default assignment for controllers[2] makes sense, and is exactly what I need.
[2]
* fader = volume (CC7, I think)
* increment and decrement buttons = octave up and down
* pitch bend and modulation wheel, as expected
