Obviously this topic will tend to be highly subjective as the tools (at least for me, ymmv) have not been different enough to matter. I personally feel it's a

Obviously this topic will tend to be highly subjective as the tools (at least for me, ymmv) have not been different enough to matter. I personally feel it's a matter of what you enjoy using more. Before Windows 7 I would have given OSX with the better user experience overall, but after using Windows 7 for the last 2-3 months, I am so impressed that I don't dread going back and forth between it and my mac at all. It's a fine operating system that is a pleasure to use. That said, for development reasons, I tend to stick with OSX simply because of the unix shell (though with how easy it is to spin up a virtual machine with linux now days, this might also not matter as much anymore). So really I don't see a clear advantage either way, I think it all depends on how much you enjoy using one vs the other, as your environment enjoyment will probably affect your productivity more than just the actual platform.