Best by far were the LCD shutter glasses some with an integral 2 channel personal stereo system which enhanced the 6 channel uncompressed digital theater sound system which IMAX uses.
With E3D LCD glasses one eye is blanked out while the other eye is transparent (or really partially transparent) as the right and left eye images alternate on the screen.
Headset costs and the requirements for cleaning, collection, maintainance and labour has limited the electronic E3D headset use. Next best is the P3D polarized glasses and IMAX has used re-usable large plastic polarized glasses which are far better than low-grade paper glasses. Both left and right eye image are projected simultaneously on the screen through polarizing filters which complement the polarized filters in the glasses. These glasses still require collection and cleaning. DMR/MPX theaters will likely go to the even lower cost disposable glasses similar to those used by competing lowend 3D systems.