I haven't taken in consideration the cost of the softwares or the free ones already present in the Mac.
Next question then...I've been on some Mac forums & the conclusion was the same : if you have a good enough video card & lots of RAM,the Mac will run well. Still,that means a lot of money paid for a top MacBook Pro,when you can run video editing softwares on Win7 for half or a third of the cost. Most softwares support Win7 & Mac,so why should the Mac perform better in editing of any kind? That's a question that no Mac user answered to me until now.
One more thing! Editing of any kind is not done on a laptop's small & faulty screen,you do it on a IPS or S-IPS LCD panel. That is if you want the best color rendation,black & white levels accuracy,180 degrees angle of view without colors washing away & more.