Well here's the trick - if I do anything that's going to be indoors the entire time, I do it in C4D. If I go outdoors and there'll be trees and bushes, etc., then I bring the C4D (or XSI - and now they're usually modified in Mudbox) models into Vue.

C4D (and XSI - which is basically Mental Ray, so you could say the same for Max and Maya) has a fairly fast renderer - the same basic objects setup in Vue (let's just say a "Living Rom" setup) would take 2-5 times longer in Vue (I think depending on the complexity of the lighting.

However, C4D doesn't handle the sheer mass poly-counts with thousands of alpha masks (like the trees) nearly as well as Vue. Something with hundreds or even a couple thousand trees will crash C4D (and most others) in a heartbeat. It's also more difficult to handle natural world observed atmo in C4D - hence the coupling with Vue.

BUT - like mentioned above, if it's a combo like the flyover... There's no problem rendering them on completely different machines with different apps and putting them together as long as they both have the same direction of sunlight. I did one called Outnumbered that way - the missile that is close up was rendered in C4D and the rest in Vue - which was then brought into AE and Photoshop for the fire, trails and glows. After I was finished I realized I should have done ALL the ships and missiles in C4D and the landscape in Vue and composite them together.

-Lew ;-)