By far this is the best lens in my bag, and my bag is stuffed with grand master lenses. I rely on the exceptional autofocus, image clarity, and stabilization. What led me to write this review is this last weekend I had a gig to photograph a corporate volunteer event spread across a 77-acre cemetery and the lens saved me from needing to run around the entire lot. I've often wondered if I should have bought the 70-200 but I regularly shoot 200+ professionally and this lens always performs exceptionally.I've had this lens for almost a year and mostly use it professionally on snow cat tours and skiing excursions. Occasionally I use it for wildlife photography in my hobby time. I'm pairing this lens with a Sony a7RV, which has great autofocus capability, and compliments the autofocus technology of the lens greatly. The manual focus is incredible as well. Usually when I need this lens I don't have much time to compose a shot, and I'm always impressed with the quality I can achieve in a quick transition / adjustment.This has become my favorite lens to work with. The 135mm marker is great too when I need to take family portraits. My average workflow with this lens is a lot of action shots and then a group photo, and while I still switch to a 50mm sometimes with the group photos the 100-135mm group photo at f/5 keeps the scenery and makes for a favorite shot. Also, the images are almost always in great shape when I go to post production, so my additional workload with this lens is usually minimal.10/10 would recommend this lens, and if you're considering the 70-200 I've often found the 200-400 range is needed often enough to warrant the 100-400.