Over 10 years ago I had an EOS system based around the -1N and the -3. I bought my EOS3 brand new at a time Canon was doing some promotions. I got the PB-E2 free, but the -3 was still near £800. I bought a few months later an used -1N.
I liked the 3 a lot. It had a lot of features and slightly lighter than the -1N. The Eye focusing worked with me even with glasses or contact lenses.
But, I liked the -1N better. It has a better viewfinder and the fact that the -3 had a square hood made it less easy to use for vertical portraits. The EOS-1N is still the best camera and the easiest on the nose for vertical shots.
I sold my entire EOS system many years ago, but the EOS-1N is one of the few cameras I truly regretted selling.