AutoCAD Inventor :: Alternatives To Studio For Animations And Renderings

I would like to animate and render a 30 second video of something similar to the attached assembly. I have been using Inventor Studio to apply animations to the components, render them as full frame AVI (800 MB files), and compress them with Sony Vegas Pro free trial (~120 MB).

The attached assembly is a simplified example and took me around three hours to model, constraints, animate, and render from scratch. Normally, the boxes are constantly starting and stopping and moving at different velocities. Defining distances and times is cumbersome especially since I need to be aware of the boxes' positions relative to each other so they do not appear to move at different speeds or overlap.

I think a solid modeling program might not be the best tool to animate loose components sitting on a conveyor belt. Inventor slows down and occasionally crashes when I get up to 40 or 50 boxes stopping and starting and moving at different velocities. I am inclined to think that 10 or 15 animated conveyor belts moving boxes with a coefficient of friction would be near impossible on my machine (modeling the belts similar to a track on a tank or a chain and sprocket, also constantly starting and stopping and moving at different velocities).

I haven't played with Showcase, 3ds Max Design, or Navisworks Simulate. Would it be worthwhile to try any of these to animate and generate videos?