I have finished ONE SLEEVE. And I have a new and deep appreciation for all the people out there in the SCA running around wearing clothes with cloth ball buttons. It took me three days to get all 26 done (in time-manageable chunks, and being as nice to my carpal tunnel as I could), and two days to put all the buttons on a single sleeve.
They're lovely and simple and soft, and I dread the prospect of putting the remaining 13 buttons on the other sleeve. It's not difficult by any means, but it's hard on the hands and fingers, and tedious, and time-consuming.
When I think of all those people I know who wear these, now I think about all the time and effort and discomfort and outright pain they went through to get there, and I'm even more amazed at their abilities and patience and dedication now than I was before.
It's worth the effort. But after I finish the mate to this sleeve, I think I'll be done doing cloth buttons for a while.