Yes it is. Pre-purchase concern was twofold, sharpness & fast AF. Now no worry as AF speed proved quite good at both ends, 200 & 600, and during zooming. Finally mastered full zooming lock-to-lock using only left thumb with no hand movements while palm cradles collar foot. Took some practice and initially sore thumb.
Now having the 7R iv the images are even crisper w 200-600.