There's a certain downside to mimicking the OS X design that you may not be taken full account of, which is that for people who have used OS X, your designs look like a not-quite-perfected copy. It's a sort of uncanny valley thing that manifests itself likewise in the common discussion of whether something feels "native", or whether you should use the OS-provided UI elements vs. re-invent the wheel when writing an app. For instance QT apps on OS X.

It's better to either do an exact copy or to be different enough that you don't invite comparison, otherwise what you've come up with will always look like an inferior copy of the original. At least until the user has spent enough time with it that it becomes the new default. But don't forget that user acquisition is just as important as long-term usability.