Now we know the weight of each of the three variants, I've calculated the achievement ratios of this generation of RX and the results are to be expected:
First Lexus did not achieve the claimed 100kg weight savings, it's 40kg for the RX 350. The RX 500h did not save any weight compared to the last gen RX 450h.
The achievement ratio is equally bad as the last gen and worse than gen 1-3, so it shouldn't come as a surprise the new gen barely got any performance AND fuel efficiency gains. The 500h does not bring anything new to the table compared to the 450h power-split hybrid system. It is also especially bad compared to the multistage power-split 500h system: the LS500h is 165kg heavier and total output is 9kW lower but is faster and has almost same fuel efficiency as the RX 500h. I've always said P2 hybrids suck and TMC couldn't do any better than other manufacturers that tried it.
So despite Lexus spending so much effort on them, two of the four powertrain options are sidegrades especially considering potential reliability degradation vs. the V6. The 350h/450h+ should be the more sensible options. Again, Lexus does not know how to build both fast and efficient ICEVs and P2 hybrids, and one should avoid them and go for their PS hybrids whenever possible.