I think this lens is really great ... but have decided it shows up the fact I have little experience of taking pictures of moving stuff at 500mm ....
Give me a wedding using a 24-70 and 70-200 any day and I can produce nice images (albeit as a second photographer next to my 'pro' wife).
The 100-500 undoubtedly can give great images ... but not, at the moment, with me taking the pictures ! I have a lot to learn about the R5 focusing system and how to remember to use a full frame camera again !! A few years away from taking photos and it will take me a while to remember how not to make stupid mistakes ... all fun though