Afaik, Macs offers some of the best PCs for designing 
I guess it all boils down to whether you want to game or not? If not then just go for the Mac? 
You'll never know until you try~
No comments on pirated software though, its a taboo here 

The new MacBook Pro 13 comes with Intel HD 3000 which is more or less on par with that of ATI5470 
Do you really need a powerful GPU for your work? 
Iinm editing depends more on processing power? Unless its 3D stuffs you're working on

Then perhaps it would be better to get something more powerful?
Dell XPS 15, Dell Studio XPS 16 are worth looking into... or perhaps Vaios?

I don't think the MacBook Pro 13 inch could handle with new Intel HD 3000
I would suggest to take the 15 inch though, it's all powerful and the price is powerful too.
ASUS or Dell
And there is hackintosh (if you would want to venture into it)
For the price of Macs, you're paying for the brand, the quality and the OS in a very expensive way 

Oh, and there's bootcamp if you want to use Windows on a Mac to play games.
Recently removed support for Vista, only 7 for now

Definitely won't lag 
Its a powerful lappy o... Even way cheaper models can handle the load...
Personally I think you should decrease the specs and spend some money on the warranty...

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