I also did a few 3d observations and what I found surprised me. These tests were done with just my CA813 light meter in fc mode at the screen facing the projector. The screen is 133" diag 16:9 and the projector is at about a 23.5 ft throw. The projector was in my normal watching settings, which is reference, "normal" aspect, d65, rec709, gamma 2.4, film mode ON (decreases FC by about 5), contrast at 88 or 89, and auto IRIS limited (i think).
In 2d, with a 100 IRE field: 19FC
WIth 2d-3d mode engaged on Sony with NO glasses.... 8.9 FC
When placing the Sony glasses in front of the meter.... 1.5 FC
So maybe I had a misunderstanding of 3d modes, but I thought most 3d modes went UP in lumen output when engaged, and then back down of course with the glasses on. On this projector, simply engaging 3d mode kills half the brightness, bringing it in line with most of its cheaper competition.
Also the 3d grayscale was way off, with the middle IREs having a strong push toward green (glasses on and off) - VERY visible. And on the spears &munsil clipping patterns, green, red, and blue were getting clipped badly unless contrast was turned all the way down to the mid 60s! I will test this more tonight or tomorrow.