Fretboard radius - how tight?

I'm wondering how tight a radius people have on some of their ukes and if anybody has found it too tight in any case. My ukes with radii are all 16" which is very gentle. I was chatting with someone who is doing a 7.5" radius and I thought that must be really tight but then read this article and it seems there are precedents for it: http://www.ratcliffe.co.za/articles/radius.shtml.

Funny thing is it seems typical radius on a double bass fingerboard is about 3.75" and I've been playing on that for years.

14" fretboard radius is very common for ukes (myamoe, collings, ...).