Memory (one can never have enough), and especially the screen real estate. I do a lot of electronic CAD work, and my employer insists that only Windows machines and Windows-based software will be supported for my work for them. So I run W10 under Parallels on my own personal hardware.
I do most of my work on my maxed-out 2010 cMP (which also survived the fire, and I've since moved it into my office at work to supplant the ancient, creaking corporate Dell tower- primarily since I currently have no permanent home to keep it in!). But I do need to do some CAD edits when working remotely, now and again. The extra speed will be massively welcome running that Windoze crap under Parallels, compared to Ol' Paint here... So I regard the 14" as future-proofing, to some extent: because if I'm going to pay that kind of money for a machine I'm damned well going to use it for a minimum of 10 years again!
Note to the humor-impaired: no Windoze machines were harmed in the writing of this post. However, this is primarily because all of them that I owned, including my company laptop, failed to survive the fire. Can't hurt 'em once they're already dead, right? (;-)