Didn't love the idea of having this lens in the lineup when I first bought it for a very specific use case. But ended up using it more and more since it was around, and ultimately ended up liking it a lot. lol
Someone asked (and then retracted the question...) Yes, people still use & love this lens. I find mine to be amazingly sharp and versatile, and have zero complaints (which is rare for me). In my opinion it has the best IS of any Canon lens I own, and I own ... too many.
Canon EOS R5m2RF100-500mm F4.5-7.1 L IS USM lens500mmf/7.11/1250s1000 ISO+1.3 EV
Canon EOS R5m2RF100-500mm F4.5-7.1 L IS USM lens363mmf/7.11/1250s2000 ISO0.0 EV
Canon EOS R5m2RF100-500mm F4.5-7.1 L IS USM lens500mmf/7.11/800s800 ISO0.0 EV
Canon EOS R5m2RF100-500mm F4.5-7.1 L IS USM lens451mmf/7.11/2000s640 ISO+0.3 EV
Canon EOS R5RF100-500mm F4.5-7.1 L IS USM lens500mmf/7.11/30s25600 ISO-0.3 EV
Great images here, this looks like a stunning lens and I know shooters of other brands would love to have this range. I’m actually considering grabbing an R5 at the current low prices just to use the 100-500mm.
A few years ago I borrowed one for a week to try out and brought it along to a couple construction site visits. For this application I really liked that it was only about the size of a 70-200/2.8. It made 'run and gun' coverage very easy because at the time all I owned longer than 200mm was the 200-400, which could have worked as well, but would have slowed me down a lot more due to size, weight, need for a monopod, and juggling all that gear. The 100-500 was great for standing back and compressing scenes or staying out of the way of messy situations, such as the concrete cutting photo, which created a ton of very fine dust. The 5x zoom range also meant I could isolate details or zoom back for somewhat wider coverage very quickly because sometimes a certain action or procedure would only occur once.
I had also borrowed it to try for field sports coverage, but for this application I was less enthusiastic about it, primarily due to its extending zoom design and the weight/resistance of the zoom ring. In this respect the new 70-200Z is much better and when paired with TCs seems to be a good alternative.