Re: Is a 14" fretboard radius a good "modern" compromise?
Lots of good points already...
I can play a 14" radius, but it's flatter than I'd want if I were ordering a custom build. The only radius I can't stand to play is the vintage 7.25; I won't keep anything more round than the "modern" Fender 9.5.
Also agreed that nut width, depth, and back shape make a much bigger difference. I have pretty big hands, so I can't stand either 1 5/8 or 1 9/16 nut widths. My preference is 1 11/16 but I can deal with a bit wider if necessary. In terms of back shape, I like a soft-V to C shape; a D or U shape has more shoulder than I like. When it comes to thickness I like between about .850 and .900 at the first fret. I can play bigger than that (like my 335), but I really can't do smaller. The smallest necks I can get along with are on my 80s MIJ Charvels; Ibanez Wizard necks are just too small to be comfortable.
My ideal neck would be a 10" radius, 1 11/16 nut with a soft V shape around .900 at the first fret. It'd blend into a C shape around the 7th to 9th fret and be close to 1" thick at the 12th fret.