I think its time for me to replace my maxed out 2011 13" with a new machine. My current usage is Safari, iTunes, Spark mail, moderate Lightroom and about 2-3 hours a week in FCPX editing single cam 4k footage. I've really noticed that the 2011 machine is struggling to do 4k even with proxied media which I blame on the ancient weak HD3000 graphics. My question is should I go for a high end 13 inch again or go for a mid range 15 inch. The 2 BTOs that I've looked at are a 13 with the 3.1 i5, 512GB SSD, and 16GB RAM. The 15 is the 2.6 i7, 512GB, 16GB RAM. So both machines are around the same cost and I'm also having to factor in a new thunderbolt dock to replace my Belkin TB1 dock and buying a couple of USB C to USB A adapters. So I'm trying to stay below $3,000 if I can.