70mm has an inherently wide aspect ratio (it doesn’t use anamorphosis) but its frame is ‘only’ 2.20:1. Thus any prints derived from a ‘full’ widescreen source, e.g. ‘blown up’ from anamorphic 35mm, will lose a little picture information from the sides.

Opinions vary as to whether a 70mm blow-up actually offers better image quality than a straight-up 35mm print, but it did have the undeniable advantage of magnetic 6-track sound (which hairy_hen has replicated for the despecialized and 4K77/4K83 preservations) and was more commonly used in big theatres for showcase screenings.

I don’t know of anyone purposefully making a 2.20:1 version to recreate the 70mm experience. I guess the real question is which cinema you went to for that first viewing? Did you go to a big screen, which might have been showing a 70mm print with 6-track stereo, or a smaller theatre showing regular 35mm (with Dolby Stereo if you were lucky)?