1920x1080 on a 15.6" screen, hmm. I hope you're a pilot or something. And either I'm too dumb or there's no easy way to find out what the thing weighs.
BTW, if you're mostly doing office and internet stuff, I/O devices should have highest priority. Screen viewing angles, keyboard quality (!), pointing device (I'd prefer having a trackpoint these days), stuff like that. If you expect some roughter handling, a magnesium case as found in better Thinkpads can't hurt. Type of external monitor connection and battery runtime at lower load are other factors to consider.
How portable should it be anyway? I used to have a 3 kg brick years ago, now I'd be aiming for more like half that. Maybe I'll get a used/refurb'd X series Thinkpad one of these days...