I think that cinema 4d has the best interface of any program that I know... maybe moi can compete (even though it is much smaller)
There are so many small things, that make such a huge difference. for example the possibility to change parameters of multiple similar objects at once just by activating them all. The possibility to use x+ or x* to edit even multiple values that are different. that alone makes working with adobe products feel like stone age. Change the size of multible comps in AE you need a script... you need a script for every second thing in AE.
If you have the impression that a workflow feature is missing in AE you can assume that you at least need a script or a plugin. in C4D you have good chances, that you just have to google it.
also the concepts behind the UI are great. I love nodes. they would also be so good in other programs.
Most of the good concepts are super old, they where already there when I started with R6. They allow complicated things with beeing verry easy to understand. mograph is also such a concept.
In younger days I unfortunately I can also name some features that imho are still ok, but less magical. all the reflectance stuff. or the material node editor. Even though it is able to deliver extremly complex results, it also feels that way. I like nodes a lot (doing xpresso for ages) and also node based materials, but I dont use c4d's often because I struggle to accomplish the simplest tasks.
But most other areas of cinema are so easy accessible and understandable. Just easy to start with but powerfull if you learn them properly.
Even though I am now very happy with resolve (fits my workflow much better then AE) I would love to see software for compositing, editing and image manipulation with the same paradigms as C4D.
best regards
Jops