Hi Leigh. Still have a lag issue on the MBP only but more localized like the black point is pretty bad or a duo tone not pretty. What I just found that helps a lot, although not yet live action filters as advertised by serif .... is switching view quality to nearest neighbor in performance prefs. Naked eye visible speed difference and so far invisible quality downside . With OpenGL only of course. If my MBP, one the fastest laptop on the market cannot resolve properly.... Hmmmm maybe I should check a font issue what do you reckon? Thanks