If you expand our discussion to encompass all three of these os's, Linux wins hands down.
It is free, it can emulate both a mac and a pc. It breaks all the rules involving the saying, "You get what you pay for." It is more stable, more upgradeable, faster when compiled on the machine it is to be ran on, etc., etc.
It is just untouchable. I have worked in quite a few shops where they will allow you to use it and just emulate the pc or mac for projects.
However, it is for geeks and professionals, it is not that user friendly (many windows users find Ubuntu satisfactory and the learning curve acceptable--personally, I prefer the Slackware flavor.) It requires you to be proficient in the understanding and use of a computer. It, requires you to have at least a modicum of engineer skills, as frequently you will want to recompile the OS from source, or some new app from source--rather than trust a binary given to you by an unknown source. Most windows users are not proficient in computer skills and/or knowledge--but they all will tell you they are. Once they gain enough skills to impress themselves, family and friends--they tend to quit on the learning curve--this is not a "bad thing" and if they are not employed in the industry, what would be the purpose becomes a legitimate question.
Bill Gates must set up at night praying that Linux never develops into the type of competition it deserves to be.
When China threatened to adopt Linux as the countries chosen OS, Gates negotiated a deal to darn near give them windows--don't think he was not quaking in his boots and envisioning the downfall of microsoft.
So, mac users should not really feel that badly, windows users should not feel that badly--but heck, the religious wars are fun, aren't they??? <grin>
Regards,
JS
another very well put comment