I don't know how much this has been covered here if at all, but I wanted to relate my findings between 3D glasses on Panasonic VT30 plasmas using the TV's 2D to 3D conversion.
I initially compared the Panasonic glasses with an aftermarket set from Dimensional Optics. This was before I calibrated or made any adjustments to the TV's 3D mode other than selecting a particular picture mode. At this point, looking at a gray ramp with no glasses, white balance looked horrible, as expected, with purplish white tones and bluish dark grays. This is common for 3D mode with no glasses on.
Then I looked at the test pattern through the glasses. I double checked to make sure they were on, and there was no doubt they were as the image darkened after pressing the power button and my laptop screen flickered when seen through the lenses. With the Dimensional Optics, the gray ramp still looked terrible, with a very strong blue emphasis at the low end. The high end looked poor as well, though not to the same extent. With the Panasonic glasses, the glasses seemed to filter out the blue emphasis in the dark grays, and the white balance looked better.
Then I measured each pair, taping them one at a time in the optical path of my Jeti spectroradiometer. I triple checked to make sure they stayed on throughout the measurements. The results can be seen in attachment #1. The difference is dramatic.
I tried to calibrate with the aftermarket glasses, but the inaccuracies were too great to correct for without severe side effects. However, I was able to calibrate with the Panasonic glasses and achieve great results (attachment #2).
Since then, on yet another VT30, I've had similar results, but this time with True Depth 3D aftermarket glasses.
Donald 3D glasses comparison.pdf 264.4853515625k . file
Donald ISF Day 3D.pdf 264.11328125k . file