Where do I start.... C4D is straightforward, if you work with joints you can mix and match them using the outliner / inspector just by drag and drop them, and same with everything else. There is little you cant do with C4D because even parts of the software you havent really used become pretty familiar to understand because almost everything uses the same drag and drop philosophy, so using it for daily work is really quick even if the client ask you to do something you never used before.
With Blender, not so much. Modeling is great, is pretty powerful and very fast to do, but everything else is the same "we are working in this module to improve it and its on the roadmap". Animation I had encounter roadblocks with infinite loop, with joints, with the key manager, etc, etc. Things that are really easy or straightforward in C4D even for someone who never used them, but in Blender you are constantly changing keys and workflow because the particular developer who did the part of Blender you are using, didnt follow the same logic applied to other parts of Blender. Or maybe did follow them in a weird way. So you end up half of your day watching videos on youtube so you can say "ohhh thats how you do it". Granted, once you know the workflow its yours forever unless you forget about it if you arent doing it daily.
Also, it gets really annoying when you work with multiple objects, something that is doable in every other software. For example, if you work with fonts, you cant really select multiple and change the text at the same time, or changing character spacing without clicking alt + enter. Using Ctrl + L to link materials, fonts, etc help to an extent, but as far as I could test not everything worked with alt + enter.
Oh and the most annoying was editing a really dense object by mistake. Sadly Blender doesnt do well dense objects, so you have to be careful not to Tab by mistake on one.
Last but not least, Blender has fluids, particle system, C4D doesnt (sorry Thinking particles)... but soon that proves to be inconsecuential because Realflow and Insydium draw circles around them. Last time I used them, you cant preview them unless you cache them first, so again, C4D is way faster to work. And again, drag and drop people! you can take anything into a mograph cloner and it will work.
I forgot to add.. OF COURSE I want C4D to be as fast as blender playback is, and OF COURSE I also love Eevee and want Redshift RT to be like it, but even if Redshift RT is as half as fast as Blender Eevee, I would go back to Maxon in a heartbeat. Right now, I mostly model stuff, so Zbrush / Blender are really really great to work with, because C4D modeling is cumbersome.