UPDATE - An issue that has gotten pretty bad is the letters are wearing off the keys - no E, S, D, L, C, V, N, M & others are showing signs of wearing off. Not sure if this is a defect or just poor quality.Overall, a great keyboard! A little pricey. Lots of useful features! One minor issue (4.5 stars?)My favorite features are the easy key remapping that can be done from the Logitech App, Easy-Switch to different computers, CAPS lock on screen notification & Quick-lock key.-Jumping from system to system is easy without having to employ a KVM.-I am a touch-typer but often hit the CAPS lock by accident, the on-screen notification keeps me from yelling in my emails.-I work on secure systems & need to lock my screen whenever I am not in front of the monitor, the Quick-lock allows me to lock my system with one key, rather the Ctrl-Alt-Del & then clicking Lock.The only minor issue is that the letters have worn off the E, S, & C keys. Many other keys have a nice shiny spot from millions of key-strokes. No big deal since I type by touch but if that is something that bothers you, now you know.