The radius doesn’t seem to matter. My guitars have a pretty wide range: 14” radius SCGC, 14" - 26" compound radius Collings, and 20” radius Froggy Bottom. They all barre equally well. I do seem to prefer 1-3/4” nut and 2-1/4 string spacing.

Nut width and then string spacing, if forced to prioritize.

I don't find a skinny neck helpful for my old fingers, but I rarely find a neck that hinders my playing anywhere near as much as uncomfortable nut width/string spacing.

Of course if I'm spending my money it better have all three.

If I don't find a tone that satisfies in the first few seconds I don't play the guitar long enough to find out if I like the nut/string spacing or neck.

• Fretboard radius can vary for me. I have guitars with 12’, 16’ and 16’-20’ fretboard radii.
• String spacing can also vary. I have guitars with 2-1/8”, 2-3/16”, 2-1/4” and 2-5/16” string spacing.
• Fretwire can also vary. I have guitars with .043” x .080”, .047” x .095”, .047” x .104” and .055” x .095” fretwire.

That said, nut width is always 1-3/4” for me...:)