I had waited for a sale, because the game has bad reviews for poor performance (it's a TransGaming port, so all the API calls are DirectX translated at runtime into OpenGL, and apparently it only runs single-threaded). Unfortunately, it turns out there's an additional serious problem: if you are using a laptop, you can't use an external keyboard to control the game - only the laptop's built-in keyboard. This has been confirmed by Technical Support and no patch is planned.
This is a serious flaw and makes the game broadly unusable for me. If I'd paid anything approaching full price for this I'd be extremely annoyed (especially as it's virtually impossible to get money back from steam, and you risk permanently losing access to all the games ever purchased from the same account). Instead I am merely disappointed that, by and large, they get away with such contemptuous behaviour. I know the market for Mac games is not huge, but after Valve showed the world how well native cross-platform releases can be done, it's distressing to see Ubisoft throw out such a careless port. Surely paying more attention to detail would be more profitable for them, long term, than getting a well deserved reputation for the worst Quality Assurance in the industry?