Thanks for your input guys.
Reading all your comments, I'm tempted to summarize it just as Rerouter said:
Its a very mixed bag
It looks to me more like a lottery to find a good working keyboard/mouse.
But as was mentioned earlier about the need for wireless input on a desktop machine, there is my context, which I feel the need to mention — less to justify my choice rather than show a perfectly viable use case for going wireless. My setup is a desktop computer, which I use as a media player and all-in-one desktop/media/gaming computer (well gaming not that much lately but you get the picture). As a result the computer sits on a piece of furniture in front of my sofa. Between both space and a low table. Distance: 2 meters.
There's an advantage with wireless and this kind of setup: only one wireless keyboard/mouse combo that you carry with you across the room lets you control your computer remotely (ofc best with large TV screen and large fonts...) from anywhere in the room. And the Trust keyboard had a fairly long range compared with anything else I've had.
All of this kind of sucks with cables. Hence going wireless with a keyboard/mouse combo and one that takes little place is even better. Moreover my computer case only has two USB sockets on the front. As most keyboards don't come with any USB hub, wired input devices would go in pair.
So the number of possibilities are very reduced. The only one wired keyboard that comes with a USB hub, which I've found in nearby shops is an Apple Aluminium keyboard. I had a USB trackball that unfortunately started to cause troubles with buttons recently (I might attempt at repairing it some day) so I resorted to using a USB mouse, connected to the keyboard.
So far, in my own case, this is the only setup that's going to last, I believe.