Frank,
Thanks for the videos and the information. Your RR is spectacular.
I am 17 years into the building of my RR. I have 72" minimum radius with 4 3/8" separation on these curves with easements and superelevation. I have a few 100" radius curves and a couple around 120". These broader radius curves have 4" o.c. and are eased and super elevated. You are so right. The broader the curve, the better the trains look.
Wishing you continued success.
Regards,
Ed