Earlier quoted context omitted.
I think if you are spending more than 10 hours per day on your laptop, price shouldn't matter. On a side note, you've missed the retina thing, it's making a true difference.
If you are spending more than 3-4 hours per day on your laptop, you should really be using a desktop, for the sake of your long term health....
But moreover, a PC forces me to do my work in a place I have dedicated to work. People are now recognizing the importance of sanitary sleep habits. Well, my PC helps me maintain sanitary work habits. Well, it did when I was working from home a bunch.
I started a new job a couple months back, which has me working from their offices on a shiny new Mac Book Pro. I hate it. I've grown to love the efficiency and instantaneousness of everything on my utterly predictable libre *nix desktop. Plus, even if I don't plan to do work outside working hours, there's a strong corporate culture of taking your laptop home--I don't know, to maintain optics of always being working or something. Either way, my employer could have saved a few dollars and made me much happier by locking a workstation to my desk.