Small issue with order of keyframing
This isn't a major issue, but just something I spotted. I was key framing 2 round cubes, (smoothed to spheres) to move apart from the same starting location and scale down at the same time over 100 frames. This gives the illusion of cell division. No matter how I tried it was impossible to get the 2 to scale down exactly the same way, despite making sure all keyframing was linear. To cut a long story short it seems that the exact way Blender handles these changes is influenced by the order the keyframing operations are set up. Because I was playing about with the cell division idea, I replaced one mesh a few times and didn't notice that I had keyframed the scale down first on one and the movement first on the other. Once I noticed this I just deleted one of the 'cells', replaced it with a duplicate and just altered the final location. Problem solved. I had no idea that the order of setting up key framing operations caused these very subtle differences. The latter were very real as I could see by the values for dimensions as I moved through the timeline. I only had key frames at the beginning and end, so I added in extra ones to solve it before I realised the cause of my error. Even that didn't help much, (although I guess I could have keyframed every frame to force the issue). I just thought I'd mention this as most wouldn't notice such subtle effects. Spheres moving apart are obviously very sensitive to tiny irregularities making them look odd. Sorry if everyone is already aware of the above.