I use Vue in combination with C4D R9.6. Only for a few weeks now, and the more I use it the more it seems to be stable 
The first few days I used it, I couldn’t get anything done. The Vue scenes were a huge 200MB scene file, with sometimes between 50 en 200 milj. polys. It always ended up locking my machine (so I thought). But after a while, and with the taskmanager permanently open in de systray (I am on PC), I managed to get all scenes opened and rendered with a few workarounds.
My workflow is to create the scenery in Vue (standalone), save that as a scene file.
Create the other props and terrains in Cinema4D, and set all settings and lights as well as camera. Save that as a “prepare_xstream” file without anything related to Vue. When that is saved, I import the Vue scene, and wait, wait, wait … until the taskmanagers shows 0% CPU activity. Then I remove the Vue lights (as I have already setup the same lights in C4D), and go the xStream plugin settings, disable the Vue camera and enable save Vue scene (this has to be done only once, those settings are kept).
Save the complete scene as a “include_xstream” file. It will take again some time before everything is actually saved, again looking at the taskmanager to know that it didn’t crash …
And when all is safe and saved, I close the project, en perform a batchrender of the scene.
I only have 2GB RAM, and once all is used the application (Cinema or the Vue plugin, I don’t know) just crashes and locks up the system. I never could manage to render from withint the open scene without locking up. But using the batchrender, I have never had a render fail.
At first glance, it doesn’t look to optimistic in favour of Vue needing the workarounds to get a result, but after the many hours, days and weeks getting nowhere (and multitude of crashes) it soon becomes a second nature to do the workarounds.
I am sure that with smaller scenes, or more RAM things can only be better.
Also another thing to note. If you use HAIR in Cinema4D in combination with Vue, you’ll notice that the post-render of the hairs will conflict with the Vue render. One solution is to turn the hairs into polygons …