for customers I had to work with their S24. Here I mainly use R20 if I need noise reduction or force fields then I use R21.
For me there hardly is any difference to be honest. The UV tools are cool, but not worth 1600€ upgrade cost. good 3D party UV tools are much cheaper.
capsules would be great to play around and for special tasks, but they are so niche, that I actually have no need for them.
I got myself a perpetual copy of octane (before it is gone). together with perpetual xparticles I will be able to productively work with R20 - 21 for quite some time.
As R25 already was at 1600€ update cost and R27 will the 2400€ Its going to be hard to come back to C4D.
But time changes anyway. I am in no hurry and I haven't encountered anything that can not be done with a R20 octane and xparticles.