"What is it about the 3.5" Model 27?"
As Pink Floyd aptly put it, "I can't explain, you would not understand."
Personally, the 3.5" is my favorite. It just has a certain je ne sais quoi.
I would love one in nickel to go with my remaining blue 3.5".
11/15/22 Update:
Finally found my nickel 3.5” and it’s sweet. I found it at a VFW swap meet, of all places.