My 16 does not have a centerboard so I can't tell you how a 16 CB sails. It was reported that the CB is a very different boat. I believe that last of the 16s all had centerboards, but it may have been an option because there are 16 XL models out there that do not have a centerboard. Email the factory and ask if the CB was originally an option or not. They are real good at responding.
My first boat had a centerboard. It was a Cape Dory 14 and I have sailed an O'Day 23 with a centerboard. I have to believe that the centerboard improves the VMG of the 16 dramatically. The centerboard on my Cape Dory most definitely clunked in its trunk when the winds got light and the boat bobbed in the waves. It was a lot quieter when fully retracted, but would till bang around a bit. Something to ask if you plan on overnighting. A banging centerboard would make sleeping difficult.
If I had the money I would add the CB to my 16. I liked the ability to change the trim of my Dory by raising and lowering the centerboard, and its VMG better than my 16. The centerboard would allow me to change to the closer sheeting arrangement for the foresail on the 16 CB.