Not too sure what you are referring to by "Ultrabooks," (something ARM specific?) but I have an "Ultrabook" and I absolutely love it. Its my work machine, my gaming machine, and my web surfing machine. It may even become my Steam Machine.

Its light, powerful, and compact. I can throw it in my backpack and forget its even there. What's not to like about Ultrabooks?

(For anyone wondering, its a Dell XPS 13 running Ubuntu)