I haven’t had a chance to use it yet but I was a bit shocked at the weight of it, I carried it around in my backpack for a few hours and it was way too heavy so you need to consider how you transport it and bring your tripod. I’m sure the results will be worth it though.
Great value lens for Canon users. I use this with a R8 and RF converter and it is all good with focussing and sharpness. I am not sure how it is in terms of sharpness vs the Canon 100-400 is ii but definitely better than the canon 2x extender with 79-200 2.8 is ii.