So I might have spent a few too many hours last night perusing Lexus forums, getting schooled on the LS.
It seems clear to me that there are two real standout models among what is, obviously, an exceptionally good group of vehicles.
One is Ron's LS 430 Ultra. The other is the 600hl. On that latter point, particularly telling were owners of both the naturally aspirated 460 and the 600 who assert that while the 460 is a superb machine, the 600 is clearly at another level. While 0-60 times are comparable for the 2, midrange passing is (apparently) something else entirely in the 600. And while the differences aren't huge, fuel consumption is better in the 600. Having driven the 460 AWD, all I can say is if the 600 clearly impresses as a superior vehicle then it's awesomeness must be truly awesome indeed.
For me, the biggest issue in purchasing a used 600 versus 460 is battery anxiety. As Ron informed me, they are under an 8 year manufacturers warranty - so the example posted is either out of warranty or nearly so. I know CPO does give me two more years (assuming the battery is not excluded) but unlike His Rocketness, I will actually be driving whatever car I purchase - new or used - for at least 4 years, probably 5. Just how costly is it when the battery goes kablooey? And is the car at least driveable when that happens, or do you need to call a flatbed?