Which to go for? Mk1 is cheaper, lighter and is parfocal but has worse lens flare and colour fringing. Mk2 slightly more expensive, slightly heavier, non parfocal, has additional coatings to combat lens flare and fringing and has a slightly better IS system giving an effective additional stop of light. Has anyone had any experience with both lenses? I would be using it on an 80D primarily with the intention of upgrading to FF sometime in the future. The Parfocal capability of the Mk1 is very appealing to me as I do occasionally make videos, however the better IS and lens flare resistance of the Mk2 also appeal to me. Hmmmm what to do??? Opinions greatly appreciated. Cheers G.