This is the first Lexus I have ever owned as a car collector. The LS 460 L has much bigger back seats than other Lexus models do. When you drive around you feel like your in an S550. You would think this car would have like 14 mpg. but this car doesn't. The GPS always comes in handy but now I don't think you could call a GPS a luxury feature. So remember, S550 vs. LS 460. LS 460 wins.
The back seat. If you ask someone who has or had an LS model if the back seat was comfortable they will say yes. The back seat is pretty close to how much space a 7 series back seat has.
The exterior design. The LS 460 looks like a plain Lexus. The LS is WAY more than that. Main point: Lexus needs to figure out another design for the LS to make it look like a luxury car.