The keys are not super quiet, but that does not bother me. That especially the space bar is a little louder (other, something schepp those sound), I find helpful. Because then I can hear if I've actually pressed. Despite of continuous operation so far I had no failures or problems with individual keys - so far just fine quality that comes at a price.
The key to clean only superficially, to avoid a debacle as it wrote another user. I am trying to tap with clean fingers as possible and to keep any food and drinks away Crumble ;-)
The main reason why I bought the keyboard is lighting. Right now, when it's hot outside, I darkened my loft. And in this case also shows the daytime lighting advantage. All labels are very legible.
Adjustable are four levels of brightness that you have to adjust again after turning off the keyboard if necessary.
The energy-saving option, so turning off the lights when not in use, the keys, I find an outstanding success. Once you approach with your fingers, it is surprising light.
The batteries last for a long time. During charging means of the flexible and sufficiently long USB cable you can use the keyboard without problems. The Beleuchgung is then turned pale.
My Conclusion:
I'd keyboard despite the high price at any time to buy me back, because I have so far found no alternative, lit another cordless model. Although the corded Logitech variant looks a bit more stylish and is cheaper, but my keyboard does not feel pledged in direct comparison - as I said, the tastes are different.