Definitely worth checking one for size before you decide to buy:
I'm just over 5'6" and find 16" On One's right on the upper limit for size.
Shame really, I'd have had a 456 years ago otherwise - everyone I know who's had one really rates them.
It's a very personal thing, obviously, and I know a few people about the same size who don't have a problem, but might be worth thinking about.
For comparison, small Cotic Souls and 15" Rock Lobsters fit me fine.