Rolls-Royce is a brand that can claim not only to be a pinnacle of luxury, but can be used as a reference for what the word means.
There is no diesel, because if you have to contemplate fuel economy then you shouldn't be shopping for a Rolls. Mild updates that took place in the past year were hardly necessary given the strength of the Phantom's appeal; the V12 is the most refined engine of any, and yet it will sling the vast bulk of the Rolls forward with ease and potency should you want it to.
Details such as the power gauge, which shows what percentage of the engine's performance you are using, only add to the sense that you are in serene command of an exclusive piece of automotive real estate.
Ride quality is also the benchmark for how well any wheeled transport can cushion its occupants; the Phantom seems to press the road into submission rather than make the effort to ride over it. If absolute, unreserved luxury is your only priority then the Rolls-Royce Phantom is the only car you need consider.