My first RF lens was the 24-105/4L, which I bought along with my EOS R. That was before the 24-70/2.8L IS came out, and I now need to decide if I replace my EF 24-70/2.8 II with the RF version. For this sort of thing, I find analyzing the EXIF data from my library to be very helpful. As a Mac user, I used to use Aperture for my library organization, and I had an app called Aperture Inspector that graphed out usage by lens, focal length, aperture, etc. I was disappointed when Apple killed Aperture, and I was forced to use Photos for my library (I've been reluctant to move to LR even though I use PS CC – mostly because I prefer DxO PhotoLab for RAW conversions but it doesn't do well with library management). Photos is bearable. I found a Mac App Store download called PhotoStatistica that performs the same analysis and graphing functions as Aperture Inspector.
IMO, the f/2.8 vs. f/4 choice is more difficult with RF lenses. For a higher-end DSLR, an f/2.8 lens means better AF performance (more cross-type points, more high-precision points) and a brighter viewfinder, and those benefits apply regardless of aperture choice. For the R-series bodies, with DPAF and the EVF, the difference really just comes down to how much benefit one derives from the more light and greater OOF blur of a faster aperture. For the 70-200m focal length, it was almost a no-brainer since over 50% of my shots with the EF 70-200/2.8L IS II were taken wider than f/4.
For the EF 24-70/2.8 II, about 25% of my images are wider than f/4, which is still a pretty substantial fraction. But there the trade off is not only size/weight/cost, it's 70mm vs. 105mm at the long end. A bit deeper analysis shows that with the EF 24-70, about 20% of my images are taken at 70mm, but looking at the resulting image sizes only a total of about 6% of the images with the lens are cropped beyond the 1-2 MP loss from correcting rotation and minor framing adjustments, so most of the time a 70mm long end is fine.
But coming at it from the other direction, with a 24-105mm lens about 25% of my images are in the 70-105mm range (applies to the EF lens when I had it as well as the RF lens). So if I have the extra 35mm, I use them about as often as I use the wider aperture. Does that mean I need both? Probably I'll end up buying the RF 24-70/2.8 and seeing which I use the most. If I had to bet, I'll use the 24-70 more but take the 24-105 when I travel.
I'd probably be fine with the UHS-I cards I have for my EOS R, but I already ordered a pair of 64 GB CFe and a pair of 64 GB SD UHS-II.