I'm an absolute beginner on the keyboard so I can't make an expert review but only a few remarks. First, the sounds are nice and soulful, unlike the other keyboards under 250€, and I listened to thirty of them, this one lets the emotion through and that's what a musical instrument has to accomplish, first and foremost.
The screen should be backlit but that's not essential. The build is strong, no ugly gaps, no misjoined plastic parts, the fit and finish are good. The feel of the keys is grippy, not too much, not too little. The controls are simple and clear.
Because it has a lower octave the keyborard sounds okay in a six-string guitar amp but much better in a bass amp, my Ampeg is the natural complement for it, and the amp's distortion is a really a good mach for the Casio's tones, no excess grit at all. Equalize more highs and mids and that's it.
One last thing about the sound, the headphones output is not just convenient, it also reveals the whole quality of the sounds, much better than the included loudspeakers, and even better than the 10-inch bass amp. I had not noticed when I played a two-notes chord slightly not synchronized with the loudspeakers.
But through the headphones output the clarity is so high that it became obvious, and allows more accurate practice. I hesitated between this and other larger keyboards but it's only 25cm wide so I can play it resting on my knees, on batteries. Or on the same table with my computer; I couldn't watch a tutorial and place the instrument on the table if it was wider.