In case others are curious, I called tech support and went ahead with this.
After backing up the entire directory, I installed 2.16 overtop of 2.14.
I ran the server and then the workstation to update those, and then opened the books with the workstation. The books were 568 Meg in size, and after being the conversion, which took just under an hour, they are about 250 Meg in size.
I then updated the three workstations, and we’re back up and running in about an hour and a half.
I’ve not had any feedback from the users, and that’s always a good sign!
Painless. (Thanks to the programmers for that.)