In short: objectively speaking, no, not really, since according to this EVO review, the 65 commands a £50K surcharge over the SL55, most of which goes towards the hand-built V12 augmented with two turbos that dispatches 612-hp and a 737-lb./ft. of torque, a figure that may draw comparisons to, like not surprisingly, a 737 jetliner. So what else is there besides the bonnet monster to run up the tab? Obviously the transmission has been uprated, the suspension tarted up a bit, the brakes grown, and the wheels made fancier. But the key to this whole expensive puzzle is "power delivery," which is what the article dwells on for the most part, in a sense trying to justify the cost in relation to the concussion-inducing speed of the SL65. But it's quite possible that the tester's post-drive headache may be a product of attempting to crunch the uncrunchable financial numbers, as opposed to just a function of the sheer celerity.