This may not be new to you guys but it's new to me. For all the times I've beaten Mega Man X4, I honestly had no idea that you could face Magma Dragoon via a hidden room using the ride armor. I've always beaten him with either the X buster or the double cyclone weapon.
I've beaten MMX4 multiple times with all of X's forms (Ultimate armor, the regular X4 armor set, regular X) and both of Zero's forms (red Zero and black armor Zero) but I never knew about this little secret room in Magma Dragoon's stage. I used to play this game a lot at a internet cafe that had consoles you could play near where I lived back in the day and I guess I was just always in a hurry to beat the boss because of the time constraint that I never looked around the environment.