so did my dad for a very long time. But in recent years he (and my brother as well) switched to a normal mouse. I haven't asked him why (I should!), but I suspect that lack of support from more recent OS revisions and the hardware just being harder to find might be a reason.

I have used the digitiser a few times and it seemed much more efficient than the mouse.

Also autocad has (or at least had, last time I looked at it years ago) a very prominent prompt where to input keyboard commands (in autolisp, no less!).