I don't notice either, however I watched only about 40 minutes of content with a few discs before putting them away. Waiting for my Avengers 3D to arrive tomorrow. I watched a little Tahiti Ultimate Wave, Under the Sea, and a bit of Tangled and they seemed to work great.
They seemed to have the same quality as the Optomas. I have only seen artifact a couple of times and they have always been at viewing at an extreme angle to the tv or from glare in the lenses from a light source behind me. I usually watch in the dark though.