I have recently upgraded to the latest version of Cheetah 3d (Mac only) Although I use Strata 3D for a lot of my work I have also used Cheetah 3d. Strata is great for geometric work, ie. Packaging and exhibitions but for more organic forms I am preferring Cheetah 3d. If you have ever tried Cinema 3D I think is works quite similarly though more simplified and a LOT cheaper at $149 for the full version.
There are also a series of videos you can buy to get you started quickly. What I like about Cheetah 3d is it is very mac like and not overly complex looking for the beginner. I have only dabbled with the new version so far and had a look through some of the tutorial videos. the materials system has advanced more from last version. If you buy Cheetah 3D 5 now you also get a free upgrade to version 6 when it is released.
You can download a trial version here
You can see a video of Cheetah 3D being used here: