I have been using the EF 70-200 2.8L II for years, which I have adored for its image quality if not for its heft.
I just got a refurb RF 70-200 2.8L from Canon USA during the recent site-wide 10% off sale on already discounted refurbished gear, making the final price too good to pass up. So far, I'm pretty impressed. The lens is small and light for its class, even more so if one removes the tripod collar. I expect I will carry this lens with me in situations where I might have preferred an f/4 zoom in the past.
I've never really used TCs with shorter zooms, just very occasionally with the 100-400L II. So that limitation doesn't bother me. It seems like a decent tradeoff for the much smaller size and weight. But of course, I understand how this could be a deal breaker for others.
I don't think the longer zoom throw will bother me too much, since I don't usually rack the zoom while shooting. But we will see. I haven't had the chance to use it except for some testing so far, but image quality so far seems very fine.
