If you don't mind me saying, that's quite a bit of focal length overlap with lenses which won't go faster than f/4... you could get rid of one of the UWA zooms at least. Not criticizing you, just curious about why the overlap and the lack of at least one faster lens?
Not sure if you mean overlap in a full kit, or overlap in what gets packed for a specific outing/trip.
For the former, I see no problem with significant overlap. My preference is to have the right tool available for the job. You can pound a fence post in with a little hammer or drive a small picture-hanging nail into your wall with a sledgehammer, but neither is optimal. I currently have 6 RF lenses (counting the one being delivered today by FedEx), 8 EF lenses, 8 EF-M lenses, and four TCs. For FF that focal range spans 11mm to 1200mm (11-24/4, 600/4 + 2xTC), with ample overlap. For ‘fast’ lenses, I have the RF 28-70/2L and EF 85/1.4L IS, and I suppose you could count the RF 70-200/2.8 as well.
That means when I’m going to shoot something, I can pick the lenses best suited to my subject(s). I feel the same about how those lenses are carried. I have an array of cases/backpacks that can hold a camera with pretty much any lens or set of lenses without empty space (unless by design when I want to also carry non-photo items).
The only thing I don’t want in my lens kit are lenses that I don’t use.
In terms of selecting lenses for a particular outing/trip, the same rules apply except with significant trips it’s preferable to have a backup body at least. Previously, I would bring an M body and a few lenses (typically the M11-22, M18-150 and M22/2). I’d use the M set as a convenient daytime walk around kit with family, then take the FF kit out later for solo blue hour / night photography. The EF-M adapter allowed the M body to serve as a backup, although I never actually needed it. Still, that’s a function the M6II cannot serve with my mostly RF kit. It’s why, if the rumored RF-S 11-22 comes out, I’ll consider an R8 or R10 as a second camera for the trip.
Regarding UWA overlap, as I typed the list of lenses for a planned urban European trip this summer (EF 11-24/4, RF 14-35/4, RF 24-105/4, RF 100-400, and TS-E 17), I actually removed the RF 14-35 then added it back. The reason is the weight difference – the 11-24 is a beast, and for the days I won’t need wider than 14mm I’d prefer to carry the lighter lens and leave the other in the hotel. I would bring both while traveling, but not carry both on any given outing.
As for lenses being f/4 or slower, I’ve found that not to be a problem for my travels. I use fast lenses (mostly the RF 28-70/2 and RF 70-200/2.8 now) for portraits and for indoor/night-lit events with moving subjects. Most of my travel shooting is outdoors at narrower apertures, and indoor shots are typically more of interiors (cathedrals, etc.), where I don’t need a fast shutter and thus can benefit from IS. The (up-to) 8-stops of stabilization with lenses like the RF 14-35 and 24-105 is a huge benefit for interior shots in locations where a tripod is not practical or not permitted.
I've tried one since a friend has it... I was not impressed side-to-side with my 100-500 and decided against it. Yes it is cheaper, smaller and lighter and darker (as in not white externally!) which are all positives... but I know if I had it and used it I would be left wanting more.
Given others’ reports, testing and —more importantly— results with the RF 100-400, I have a reasonable expectation the lens will perform well. Did your friend properly test the lens when new, or did you? I ask because QC is not perfect and bad lenses are shipped. I had to return the first copy of my Rokinon 14/2.8, the second performed as expected. All my Canon lenses have been fine, but for example (I know I’m repeating myself from other threads), when I was reviewing the M18-150 for TDP, my results were much better than what Bryan showed in his ISO 12233-type charts. I told him that, and he ordered and tested a second copy of the lens and it was much better, those are the results now on his site. While such issues are more common with consumer-grade lenses, they happen with L-series lenses, too. Bryan tested four copies of the EF 24-70/2.8L, the first two were sub-par.
My RF 100-400 arrives today, I’ll properly test it next week, if it’s not up to snuff I’ll exchange it, and if the second copy also fails to perform well I’ll probably just return it and decide whether or not to take the 100-500L on the trip.
