At first I had the impression that they would be darker than the known to me glasses, but that was mistaken, the direct comparison, all glasses were equally bright. It is not heavier or lighter than normal shutter glasses and you get used to it.
Some may interfere with the blue flashing glasses (exactly in the middle between the glasses), I was able to ignore the date well. It may also be that in some glasses the clip slightly forward "depends" (with me because my eyeglass frame somewhat broad fails), but even that does not harm the 3D effect.
Addendum: after probably a half years, the spring is broken for clamping the glasses so that they only can use "loose". The spectacle itself works but still.