I only tried a friend's, and it was cool. Personally speaking, I cannot work on a any keyboard without a Numpad, since a lot of my work requires entry of numerical data. I love the look these high-end 13" laptops, and I am intrigued as a geek, but I can never fit them in my work flow.
I use an 2012-ish 17" Asus gaming monstrosity. It's not easy on the eyes, but it works for me and can run Batman Arkham games at 50+ fps.
But then it would mean adding yet another thing to my bag when moving around. I hope Surface book succeeds so they come up with 15" model with a numpad.