Good but not great

RLight wrote:

Something like the 24-105 f/4-7.1 IS STM sounds more up your alley at 395 grams.

As mentioned earlier in another post, 24-105 f/4-7.1 IS STM is nearly equal to my current 18-140 f/3.5-5.6 in terms of equivalent light gathering on longer end of zoom range, which lowers my excitement some And 105mm is unfortunately too short for my shooting stile while traveling. Would this lens go to ~150mm, it would appeal to me much more.

Likewise, I might even suggest you look at the M system and it's EF-M 18-150 and EF-M 22mm f/2. Those will give you something more powerful than your D5500 (if doing the M6 Mark II) and more reach, and probably sharper too as it's a modern mirrorless optimized optic, and even smaller, lighter still in terms of whole package. One can shoot those two lenses alone and cover a lot.

I love EF-M 22mm f/2! Enjoyed this wonderful little marvel a lot while using it on tiny Canon M100. Wonderful package. Small, cheap, competent. Probably even too small for my big hands, I was sometimes missing a decent grip Still, on Black Friday I was seduced by a kit of Canon RP with RF 35 f/1.8 IS for an unbelievably low price, thus M had to go.

Yes, I was thinking about this EF-M 18-150 a lot, but the EF-M system would be more expensive than equivalent Nikon DX one (I paid only 350€ for used Nikon D5500 with 18-140 lens vs. probably over ~1000€ for e.g. used M6 II + 18-150). Also I still wanted to use my very useful Nikon 85mm f/3.5 macro which simply does not exist in EF-M realm.

In summary, with EF-M you brought a valid option, just it was not most optimal for my situation.

From having shot the 70-300 IS USM II, I'm curious how it'll do on the long end of things with the newer 1.6 firmware on my EOS R.

I would love to hear about comparison of RF 24-240 with 70-300 IS USM II on equivalent focal lengths if you will find time for it!

Essentially between the RF 24-240, RF 28-70, RF 35 and G5X II, these are no lens swap answers. The former for things like the zoo or other outdoor outings with the family where I want to be prepared for the unexpected but not have to deal with bags or lens swaps, the RF 28-70 covers events and special occasions (unless the 24-240 supplants it), the RF 35 covers indoors and the G5X II covers hiking (where I don't want the RF 24-240 as to your point, it may be light for what it is, but it's not light or compact at all per se) or other pocket-needs like glovebox duty, going to general things like the park (if it'll ever re-open), etc.

This sounds like a good selection of right tools for different jobs. I normally use 24-70/2.8 on full-frame for events and your RF 28-70/2 should be even better than that.