Lexus sure does seem like they are going backwards as far as weight, the GS350 have gain almost 200 pounds since the 1st gen. Even with all the added electronics and safety items in the new Lexus, the additional weight should have been compensated with light weight material and engineering.
I think Lexus have squeeze most of the power out of this 3.5L engine already. To gain significant more power, it will need a new engine or some sort of force induction.
The big screen is nice, but 1/3 of it is use for other controls, so the screen is not really any bigger than the competition. Also, we are talking about a car here, its not a video game or a TV set we are buying. How well the GS handles remain to be seen, the 1st video already said the BMW had better steering. The GS in that video also have the F-sport package, for it to be a fair comparo, the 5 series should have had the M-sport package and the E350 should have the AMG package.
As far as reliability, my old 2008 GS350 spend more time in the shop than my German counterparts. All my other Lexus has been very reliable, my GS350 was an exception.