The R5 is only 2.1lbs which sounds great. I saw it introduced on Gizmodo a while back and it sounded promising. Until...

My immediate complaints with not having seen or used one in person, would be the absurd track pad and the corrugated palm rest area. Why would anyone want or even think a circular trackpad would be at all useful or even attractive for that matter? The trackpad is also inset very far into the plastics which in my experience makes for an excellent crap-collector, but a terrible tactile experience (my GF's Toshiba Tecra is like this - and that machine is suited for nothing more than the trash heap).

What about a Fujitsu T70 or Sony TX90? Both are also listed on the same site you linked. Fujitsu also has a decent looking (and light) Lifebook Q series, which seems pretty thin, but has a bigger footprint sporting a 13" screen.

There's also the Fujitsu P1510 which has a rotating touch screen if you ever need it.