My major is CS and I want to buy a mac or is there something better?

First I want to buy a laptop that I hardly play on it that's why I will prefer Macs but I can control myself if there is other laptop will give me the same performance.

that's my 4th semester and I will start Computer Graphics and artificial intelligent. I want to know if a Windows or Macintosh will have any difference?

Talking about the laptop I was thinking of MBA i7 and 8GB rams with 265 SSD $1549. then I got permission to buy the MBPr the 15 inch the $1999 one. do I save the $450 dollars or i go for it? it's a big discussion for me so if anyone got a friend in CS please ask him. especially if he is doing masters that will be great.

P.S. I was thinking of buying Alienware but it's so heavy I know the MBPr is heavy but I am pretty sure it's lighter than Alienware.