I hate using the word sheer but I am going to have to.
The sheer number of pc users ( because of affordability ) means that numerically there will be more problems reported with pc's. How this translates statistically as a percentage I dont know, I do know of friends having problems with their macs and they dont even do anything rather than casual surfing and word processing. The mac users I know are trendy, like to prove it and dont do anything with their investment. In addition, I was in a real studio the other day and the owner was cursing his Mac for freezing mid process. So there you go.
Mac as the go to machine for music is a myth. If you set up a pc properly and dont surf for pornography or download every appealing free app that takes your fancy then you can have a fault free user experience.
With the money you save you can buy - well, that's up to you