Design
Scott: The thinner designs of the MacBook Air and Samsung Series 9 grab my eye; to me, the Portege looks like a clunker by comparison. Hard to beat the Air, really. That blade of metal is more elegant than the curvy Series 9, which feels like what it is: a design knockoff of Apple's laptop.
Size/weight
Scott: The Air and the Series 9 are both less than around 3 pounds. The Portege's not as light (3.2 pounds), and it's also thicker. The MacBook Air is the thinnest laptop, even if the Series 9 comes awfully close. An Air and a Series 9 held together feel like the size and weight of a normal notebook.
Display
Scott: That superbright 13-inch screen on the Series 9 has great viewing angles, almost as good as the iPad's; it beats the MacBook Air's higher-res, less poppy display. The Portege's screen is pretty good, too, but nothing notable.
Keyboard
Scott: I love raised keyboards, and all three of these laptops have them. The Air and the Series 9 are incredibly similar; the edge goes to the backlit Series 9. The Portege's larger keys might be more comfortable, but we'll take that Series 9's backlight.
Touch pad
Scott: Larger is better with multitouch pads; the Portege's still-large touch pad feels like a postage stamp compared with the epic space on the MacBook Air's clickpad. The Series 9's large pad comes close, but it's slightly smaller and less responsive.
Ports and connections
Scott: The Portege has the normal laptop features, because it's a normal-size laptop...comparatively. Between the thinner laptops, the Series 9 has the Air beat on ports, but they're small and tucked away behind flip-down doors, which gets annoying. Convenience: the Air. Choice: the Series 9. A normal laptop experience: the Portege.
Battery
Scott: The Portege takes the crown with more than 7 hours. The Series 9 comes in second with 5 hours and 22 minutes, which is not bad at all for a thin laptop--but for run time, go with Toshiba.
Value
Scott: Clearly, the under-$1,000 Portege is the winner here--but you'll be going with a porkier laptop. The Air and the Series 9 make you pay for their ultrathin designs. At $1,649, the Series 9 makes the Air look cheap by comparison.