Zero power usage.
Infinite dynamic range.
Infinite color gamut.
Automatic match between viewfinder illumination and scene illumination.
A total dynamic range (bright sun to night scenes) equal to the scene, which can be about 10-12 stops more than an EVF can manage.
Not to be picky.... but.....
Zero Lag.... not quite... it's about .5 microseconds for the light to travel through the prism.... but that's about a 30 thousandth the time of the best EVF's... for the stuff I deal with at work, .5 microseconds is freakin' slow!
Infinite dynamic range and color gamut? That would require travelling through a vacuum... you loose some of each passing through glass and through atmosphere.. It is certainly far superior, but it is not infinite....