well i noticed at the gadget show that there was quite a difference in 3d quality between manufacturers. I wasn't impressed by the sony or panasonic tvs but the samsung and LG tvs performed very well with great 3d depth. one thing i found out is the headache issues seem to be caused by flickering on the glasses. but this isn't anything to do with a problem of the glasses but energy saver bulbs and fluorescent lighting as these flicker slightly and the glasses pick this up. turn the lights off and these issues are gone.