Maya and Motionbuilder here.
We’re a tiny studio in Santa Monica but we’ve been able to handle the outsourcing for much larger studios thanks to Motionbuilder. We use it for previz, layout and final body animation. We have a robust pipeline for automating almost anything redundant as well as quality-of-life tools for animators.
The only thing we’ve used Maya for recently are for client facial animation and rigging pipelines. Of course Maya is capable of so much more, but most of our work has been delivering final body and facial animation to clients, and MoBu is our answer to that!