I prefer the ThinkPad X1 Carbon because of the no nonsense business laptop look of it. The fact that the screen can fold down flat is nice an actually came in handy from time to time when using my IBM ThinkPad T40. In terms of overall size it sits in between the 13" and 15" Samsung Series 9 so I'm not sure if you consider that bigger or smaller for your taste.
While I am partial to the ThinkPad X1 I would not personally buy it myself because I prefer a laptop with a DVD drive and a somewhat high capacity standard hard drive, yet light enough to carry around if necessary. Like the ThinkPad T430s or the upcoming T430u.