I traded in my MacBook for an i7 ATIV Book 9 Plus about a year and a half ago. The Samsung was (I think) thinner and lighter than my Air, but had a higher than MBPr resolution display and i7 processor. Basically like a high end MBPr in an Air form factor. The Samsung was a pretty dramatic upgrade and I sold my MacBook almost immediately. I only miss it occasionally when I'd like to be able to build an iOS app.
Today, I'm using a Surface Pro 3 and actually like it even better than the Samsung. There's something impressive about being able to carry a full i7 development machine around like it's a thin, hardcover book.
I don't use the Surface Pro 3, but my friend does. He used it as his work "laptop" for the duration of a gig at one company. The dock attachment is a good addition if you want it for that purpose, but its tablet form factor makes it work better than any laptop I've seen for being productive off the office desk, like sitting in front of the fireplace and writing a bunch of text. His use has convinced me that if I ever need to get a new personal laptop (my company provides me with the only one I use) I would get the Pro 3.
I use a desktop as my main dev machine, and I haven't tried to supplant it with any of these portable machines, just supplement. I do run Visual Studio, WebStorm, Photoshop, etc. on the Surface though, no problem, to code and push real features.
The docking station and a large display or two would probably be a must for using it as a primary machine. I haven't tried the docking station myself, but I've heard lots of good things about it.
Today, I'm using a Surface Pro 3 and actually like it even better than the Samsung. There's something impressive about being able to carry a full i7 development machine around like it's a thin, hardcover book.