I currently have a 2012 rMBP 15" and it's excellent except for it's size. I also have a 12.9" iPad Pro which has supplanted it greatly. I'm looking at getting a 12" rMB and in four or five months or whenever refreshed i'm looking at getting a 5K iMac. I do e-commerce for work and consume content. I'd like to dabble in iOS development but that won't be for a while. I'm debating if I should just keep my 15" since I use my iPP mostly anyway and eventually get an iMac or whether or not a 12" can suffice as an only machine for a few months. My dream setup is 27" iMac / 12" rMB / iPP. It certainly makes sense to keep the 15" as the 12" rMB may seem redundant but it's just so tempting. I don't use ports very infrequently