Hello, I want to buy rMBP and I am not sure which one will suit my needs. Mostly I will use it for developing apps (Xcode), movies (HD), music and web browsing (no games). I also intend to use a monitor at home so I can connect the rMBP to it. 1. Should I buy the 13" or the 15"? is the GPU that only the 15" model has is crucial? the 8GB ram is also an issue with the 13". 2. The recent upgrades (Early 2013) are not yet available where I live, so should I wait for the upgardes or they're not that significant and worth the wait? Thanks for your help.