Described by someone who never used it.
It is not something I could live with as a primary system. However, my woman does, and it's fine for her. I have a big beefy desktop that I do most of my work and personal power stuff on. But the rMB is great for being on the road, of relaxing around the house.
Beyond FaceBook and web surfing, it does a pretty kick-ass job with MS office, and that's how many of us pay the bills. I can also do the normal iLife stuff, without breaking a sweat. Does Photoshop OK as well, though I haven't taxed that yet. And that's pretty much what i need it for. If I'm doing anything more intense it'll be on my desktop, where I have a quad core and three 27" displays waiting for me.
This is not a video editing or game machine. But for the way that many of us earn a living (MS Office, mild creative, etc.), it's pretty darn good. People may laugh at the 1.1Ghz rating, but that's base speed, not where the CPU spends most of its working life. These systems are built to spend a lot of their lives running faster than that, not just minor spikes and throttling. Fact of the matter is that these little buggers run MS Office and similar apps as good or better than the MBAs from a couple years ago that many are still using right now. they're not screamers, but not useless slouches either.
It's all about compromises and preference. I recently tried a new 15 rMBP for a bit, for its power and screen. At the end of the day, I was still longing for my desktop with three big displays. What I realized was that, for me, there's not a huge difference in productivity between a 15" screen and a 12" one, as long as they were both retina. For me, they all pretty much suck, because I constantly find myself wishing I was at my workstation. So, might as well make my mobile light and small, while saving the real heavy duty work for when I'm back in the home office.
But no, these are not Facebook machines. I will admit that I suspected that as well, until I started stealing the woman's machine and she told me to get my own.
It's a Facebook computer. You wouldn't use it for any serious work. An iPad with a built in keyboard is how I've heard it described.