I have had this lens for well over 6 months and love it! It is pretty sharp through most of the range maybe a tad softer at the longest 500mm. The focus speed is zippy too! The only real major downside is the weight 4.2lbs. I agree with everything I read in this article and especially sharpness on the D800 as I own a D800 and D3s. Kudos for another well written article/review!