Dan, yes the Mac & Windows versions are definitely different. Why? Not really sure. They don't even LOOK the same. The project file extensions are different. They run on different engines. Yip, pretty different. There are some things that the Windows version does as far as how it handles zooming and transitions that the Windows version does that the Mac doesn't and vice versa. Like I said, the Mac version is actually VERY similar to Screenflow.
To join in with JW on the evil side here though, answer this question, how many SME's ARE actually good at presentations and voiceover?? ZINGGGGGG!!! lol. Ok, ok, ok, ok, yah, yah, yah, you do drive the content, but STILL!!