What lesser performance? Win8 performs at least equal to Win7, so no performance loss there. What stinks in Win8 is the GUI imho.
Mac has some distinct advantages on the Win environment. There are plenty of posts around that offer a list of them (use the search feature here on the forum).
If you are using a PC/Laptop, my suggestion is usually to make it dual-boot. So you can have one startup setting for general use and one just for DJ-ing. You could even opt to have Win7 installed for DJ-ing and Win8 for general purpose.
If you split it like that, stability needn’t be an issue with Windows and performance should be plenty on an i7 PC. Just make shure you strip everything you don’t need for DJ-ing, switch of bluetooth, wifi and all other stuff (like the soundcard that’s built in!). No antivirus, no index/search engines, nothing.
Hope that helps some. If you have a more specific question, just let us know.
Greetinx,
Chuck