I purchased what I assume is a PC keyboard with USB connection. The windows key is on the top row with function keys. I use a Mac, but had not trouble using with a Mac. Mac allows you to switch Ctrl, Alt (which they call Option, I think), and Caps Lock, via System Preferences/Keyboard menu. The Windows key works as the Apple key.
I loved the Avant Stellar keyboards. Have owned three. 2 finally failed, and one is still going strong.
The Unicomp is louder than the Avant Stellar and a bit less sturdy in feel. Keys make a click-clack sound--not a deal breaker for me, as I kind of like it.
For me the big deal is function keys on the left. I've programmed many mini-routines, over the last two decades, onto those keys and muscle-memory makes typing automatic. Especially useful when I create indexes (extensive ones for academic works, history, politics, etc.) which is my day job. For writing fiction I tend to write early drafts in XyWrite then import to Word for minor revisions.
I'm considering ordering a second Unicomp as insurance against the other Avant Stellar failure, as I have two offices so need two systems.
Lisa Kleinholz