Any reviewer of notebooks MUST state the capacity of the battery, unfortunately the review in THG didn't do this, so the battery review seemed to be very short for the SONY PC1V.
However if you check the ASUS and the SONY websites, you find there that the ASUS got a 46W battery and the SONY a tiny 20W battery, thus the SONY got a 2.3x smaller battery.
Since there is not yet a portable notebook (a notebook you can use while standing and walking, current notebooks require a surface like your lap or a table) a battery life of 2hrs is normal use is sufficient in the industry.
Battery run-down and normal usage can be a HUGE difference, since the run-down tests stresses the whole computer all the time and is a worst-case scenario. While a "normal" usage depends on how you use the notebook, if you only type in Word/Excel or browse the Internet you can expect a much longer battery life. Here you will also find a BIG difference between Transmeta and Intel due to different power down states etc. Unfortunately there is no standard becnhmark for "normal" use anymore, Veritest used to have one a few years back, that gave the ACER Nuovo a 11-hour battery, while Battery run down gave it 6.5hr. (The Nuovo had a heuristic power management)
What the review also failed to inform was that the SONY notebook can be upgraded to double and quadpacks (these ofcourse weigh more) to double and quadruple the battery life. If you need a 10hr or more battery life there is this option in the SONY, while not in the ASUS.
With the quad pack (4x longer battery than the ASUS), the weight of the SONY would still be HALF than the ASUS notebook, unfortunately this was not stated in the review.