At the moment I run Construct 2 on Mac via parallels desktop. To be honest, it is very likely running on Windows. I have worked with C2 on Mac for nearly a month and can't find any issue here. In addition, the speed is really fine although I only have a mid 2012 Mac 13 with min opt.
Also, I develop cross platforms app for iOS , Android, BB and even WP8. Everything work fine on Mac.