The review is mixed/negative because Surface RT promised the hope of more productivity on a tablet but doesn't deliver. Importantly, the author does note that there is a higher priced surface (running on an Intel processor) that might get closer to PC productivity. I thought these quotes were worth re-posting:
"The laptop is about as far advanced as one can imagine. The MacBook Air and a horde of ultrabook clones are hitting a brick wall in terms of form and physics. The tablet, likewise, isn't exactly pushing civilization forward; it's still fundamentally a luxury device, a delightful toy for reading email on the couch or watching Netflix on an airplane. Nobody needs a tablet. It's a lovely, superfluous thing. But everyone needs a computer, unless you're planning on living by a lake and trading furs for a living."
" Desktop mode is entirely worthless in RT, a cruel tease of non-functionality. It'll only remind you of how much you can't do with your Surface, and is going to confuse the living hell out of most people who buy one—especially when Surface Pro, built on x86 architecture and perfectly compatible with all of those legacy programs, steps in a few months from now."