Your bad experiences aren't universal. If the movie is specifically shot for 3D then it shouldn't be blurry, the limitations of the technology (and our eyes) is

Your bad experiences aren't universal. If the movie is specifically shot for 3D then it shouldn't be blurry, the limitations of the technology (and our eyes) is well known and accounted for. As for it being too dim, you might have problems with your theater not operating the light at the required brightness level (the bulbs are expensive will last much longer if they are dimmed a bit).