I’ve literally put 12000 miles on mine without any massive hassles. Tbh, just check them regularly and follow the maintenance schedule. They can be serviced quite easily, if I can do it most folk can!
Aye I've serviced RS4 hubs, got them on a set of wheels already which take much more of a wintery gravelly hammering, pretty gross after 6 months but still smooth. No issues in that department.
I've ordered the hubs and the bits. Option is there to take some spare bits n pieces.
I actually have RS4's on my gravel wheels and having looked into it, I think you are right. Good availability too.
Can tuck away a set of bearings in the kit as well.