The Panamera felt dulled and dull next to the slower Rapide. The Aston never got away from the Porsche because the Panamera's traction and torque could recover any lost ground on the shortest straight, but it was a strangely remote and joyless experience by comparison.

Where the Porsche makes more sense is in everyday use; you don't even need to sit in the back of the Porsche to know it wins the space race with derisory ease. But its advantages stretch further still. It is a far easier car to operate. There's no glass starter to plug into (and fall out of) the dashboard, no illegible dials or unintelligible navigation.

The Panamera also offers Porsche's best interior (left), a place of genuine luxury and quality from which to watch the miles flash by, and one fully commensurate with the six-figure price tag.

Anyone familiar with any Aston cabin (below) since the launch of the DB9 nearly six years ago will find no great surprises in the Rapide's driving environment. It gives the impression of having been designed more to be looked at than operated, and in that regard it has aged well. But it's not just its layout that's inferior to that of its rival. All around you can see where Porsche has been able to spend more money finding better solutions. The Panamera's seats are more comfortable, its ventilation is more effective, its headlights are more piercing, its driving position is more variable, its on-board stowage opportunities are more generous.

In more practical terms, the Porsche will use a load less fuel than the Rapide and, thanks to its gargantuan 100-liter 26.5gal fuel tank, will require refueling even less often – though it should be said that we were pleasantly surprised by how far even the Aston could be pedaled between stops. And there's not just more room in the back, there's hugely more in the Porsche's trunk too, whether the seats are up or down, and when families use cars such as these for holidays, such considerations are important.

Important, too, will be the Panamera's four-wheel drive for anyone fancying a blast to the Alps for a few days, a trip for which the Rapide would be wholly unsuited, for a range of diverse reasons. Interestingly, however, we'd put the Aston down as the quieter car. Huge work, including the installation of double-glazed glass, has been done to make the Rapide the most refined Aston in history, and in the way you can hear the V12 when you want to, and not when you don't, all of Aston's targets in this respect appear to have been met.

Should we have expected more from the Rapide, particularly as it costs almost half as much again as the flagship Panamera? That was never likely; for every Rapide built by Magna Steyr in Austria, 10 Panameras will be built by Porsche in Leipzig. Now, as ever, Aston Martin will be asking its customers to trade ability for exclusivity, that extra level of designed-in functionality for a less tangible but no less important slug of designer desirability.

For me, in this case at least, it's a formula that works. I admire the Panamera and can see how such abundant talent and the way it has been refined by Porsche's peerless engineering know-how may appeal to those happy not to focus too much on how it looks. And, crucially, if you are looking for a business tool, there is no comparison to make; it is the Porsche you must have.

In truth, the Panamera has but one serious failing, and that is its inability even to communicate on an emotional level, let alone convince. I cannot recall another car for which I have felt so much respect and admiration that has left me so unmoved.

And this is exactly the ground upon which the Rapide treads with such confidence. No, it's not as technically able as the Porsche, but it's far closer than you'd think. And whether you look at it, listen to it or just get in and drive it, the Rapide grabs your heart on your first meeting. Even now, some days since the end of my brief encounter, it feels disinclined to let go.

So while you may think you need a Panamera in your life in the way that few, if any, will need a Rapide, so too will people desire and even burn to own the Aston, feelings it is hard to imagine ever popping into the head of a prospective Panamera buyer.

Which is the better car? The cheaper, quicker, more spacious, efficient, functional and useful Panamera. Which would I have, given the ability to afford either? The Rapide, without a second thought.

Andrew Frankel/Autocar