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I had an mba 2013 for a year and it struggled with video.
I found the 15" Macbook Pro Retina to be a powerhouse with a great display that was well worth the additional bulk.
It really isn't that big of heavy in the scheme of things , unless you consider a book a heavy object!
The MacBook is for people who want to do super-light computing on the go but need more than iOS has to offer.

It's like an iPad Pro running OS X .
 
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