I currently own a 13" i5 2011 MBA. I want to get into photography in a big way and I am currently deliberating over a 5D MK3 or a D800. Would the MBA become a worthy workhorse or would I need to purchase a MBP? I used to have a 2010 15" MBP but sold it due to its size, and benchmark test of the 2011 MBA. I am mindful that the little fan will be screaming whilst using Lightroom/CS5/FCP. Also can it cope with a 27" external monitor? Thanks.