The OS X "version" is a nightmare. It's guaranteed to break with every major OS release. Nuance takes months to release working versions. When it does work, it's hostile to any other apps that use the accessibility hooks, such as Text Expander, Alfred, etc., which would be awesome with speech input.

The history of the Mac version (acquisition of a company that licensed the Dragon engine) means that it and the Windows versions are very likely permanently divergent. Given the relative market sizes, the Windows version has the best development, the best recognition, and the least schizophrenic product support.

I am glad that dictation (apparently powered by Nuance's engine anyway) is to be included in Mavericks, including a disconnected (i.e., non-Siri) mode. Maintaining an application with a skeleton crew and relying on system services that change at a fundamental level every couple years is not a path to customer satisfaction.