The Genesis version actually has most of what the SNES version does but the PCE version doesn't and vice versa, plus cool unique features like the arcade intro cinema, animated continue faces and Group Battle mode.
It's only technically limited in some ways with its graphics and sound. If its aesthetic limitations were brought up to par with the other ports, it'd probably be considered the most complete home version.
Today I added comments about the music fade outs and screenshots with a blurb about the censored Genesis intro.