I went through two K800s before giving up and getting a mechanical. The K800 is buggy and broken.
The first K800 I owned, the spacebar broke off within 2 hours of using it. I sent it back for a replacement. I was a lot easier, and cautious with the replacement, which ultimately hindered my typing ability.
There was some kind of key ghosting going on that disallowed me to type "ID" too fast. The D would always miss. I had to purposefully slow down when typing things like UserID, ProductID, things I type all day every day as a programmer. That was the last straw for me.
Just off the top of my head I count over $1000 worth of logitech stuff I own, but the K800 is the first product I would recommend against.
I am glad you wrote because I used the K800 for only 2 weeks. (I bought and returned a K800 because of a consideration that is relevant to only a tiny fraction of users.)
I have owned three K750s though. The K750 is a lot more likely to break than a good mechanical keyboard is, and the (silicone membranes in the) keyswitches get mushy a lot faster than mechanical keyswitches do, with the result that even though the acquisition cost is a half or a third of a good mechanical keyboard, the total cost of ownership is not any lower than with a mechanical keyboard, but I prefer them because their durability is within reason, they're very thin (short in the vertical dimension) and they're more "convenient" (specifically, they're wireless, and I can pick one up with one hand).
The tactile experience is almost as good as with a mechanical board. 90 or 95% as good, in my experience.
The first K800 I owned, the spacebar broke off within 2 hours of using it. I sent it back for a replacement. I was a lot easier, and cautious with the replacement, which ultimately hindered my typing ability.
There was some kind of key ghosting going on that disallowed me to type "ID" too fast. The D would always miss. I had to purposefully slow down when typing things like UserID, ProductID, things I type all day every day as a programmer. That was the last straw for me.
Just off the top of my head I count over $1000 worth of logitech stuff I own, but the K800 is the first product I would recommend against.