We're probably thinking about very different work environments.

Redundancy is more about not having a single point of failure. If you have a need for a redundant system, having a single point of failure in the KVM means you no longer have cc a redundant system.

For me, I find it simpler having a dedicated keyboard and mouse per computer, mainly to avoid the mad wiggle of the mouse to find the cursor, and then wiggle again because you found the cursor but it's not moving, has it crashed? Oh that's right, I'm using a KVM, and I'm controlling the computer that's over there. With dedicated keyboard and mouse, it's always obvious which machine I'll be controlling. And yeah, I meant slower to switch. You need to move your hand off the keyboard to press the button, then move your hands back, usually having a slightly awkward pause when it takes a moment to register the switch. With dedicated keyboards, you move your hands once, done.

And I can think of plenty of scenarios where you want to do an action at the same time on two machines. Want to compare two copies of a document across the two machines? Left hand on page down for one machine, right on the other. Trying to test a bug that mucks up the timing of a jump in a game on one system but not the other? Spacebar at the same time. Going through the same install process simultaneously on 4 machines? It either takes four key presses on different keyboards to select an option, or four key presses and four KVM button presses.

For a lot of stuff, KVM is the way to go, especially if you tend to just do a bunch of stuff on one machine, then do a bunch of stuff on another. For a lot of situations though, such as if you're having to only do occasional stuff, or doing lots of small things on different machines, it's not the way to go.

I did not expect to be writing such a detailed essay on such a trivial thing today, so thanks for coming to my TED talk!

One of the operator pulpits at my work can be run by one pulpit operator, but commonly has multiple people in it - someone is almost always being trained, floor operators hang out on break or when maintenance has to take the machine for a while, lead operators and supervisors and quality personnel stop in to monitor. They have I think five computers, all with their own keyboard and mouse. The operator mainly interacts with just one, and the others are set up for reference spread all around the edges of this room that comfortably holds five people. It works pretty well because the auxiliary people can look stuff up on the reference computers without having to take away keyboard or mouse control from the operator, and with how physically distant some of the machines are from each other, a switched keyboard would have to get carried around the room which would be annoying.