Maybe it's just the one I have, but after some years of usage, mine went into retirement about half a decade ago. Sometimes I like to take it out and use it thinking I'll have some retro fun, but then I'll remember about all the broken and sticky (endlessly repeating) keys it has. No fun! Again, I don't know if that's a common problem or not, for older ones to have bad keys. I have 2 or 3 Apple Keyboard II's which are just OK, though.
I used to have two, then I gave one away... but now I have two again. Anyway, there seem to be two different types, I noticed. One is curved on the bottom, around where the ADB port is, and the other one (which I think is the one I gave away) had a V-shaped plastic instead of round. Anyone have these or know about the difference?
Also: beware the ADB Mouse II, which is round. I have about 5 or 6 of these things, and only 2 or so are good. Why? The clicker goes bad! The original blocky ADB Mouse: much more reliable, though it is a nice bonus to have a heavy gray mouse ball, not the light-weight black one.