Animation and Autodesk still have a long way to go in my opinion. Other engineering computer aided design software programs may have anmation sorted out and seemless, but I feel Inventor in particular, still have a very glitchy platform for 3d animation. You only have to google, or Bing errors with animation using Inventor and hundreds of links will pop up. Having said that if you need to illustrate a simple bolt up or motion procedure Inventor 3D seems to handle th accuracy and getting the message across quite well. Mostly animation is dependant on your PC performance capacity. 3D modelling is always stressfull on RAM and CPU, not to mention the compulsary need for a high end graphics card.
I have created several animations now, even on quite small files, and Inventor seems to reach its animation limits before too long. In contrast to 2D drafting, most seem CAD software programs seem to be able to get away with your regular home based PC.