Have just taken delivery of a new 3.0 (240) Sportbrake Premium Luxury - I specified 17in wheels in an attempt to minimise the "jiggly" ride over poor-quality roads (aka anywhere in England!) I tried a Portfolio first (standard 19in wheels) and that was horribly uncomfortable - Heaven knows what the blingy 20in wheels feel like! Then a Premium Luxury with standard 18in wheels - still not up to historical Jaguar standards of ride comfort (like "Old Peters" S type). Predictably, as delivered (on 17 inch) it's better, but still not what anyone could call comfortable. (Given that I'm built more for cake than speed...) Not as comfortable as the well-run-in "Luxury" I test-drove; but I don't know what make of tyre that was on. It's arrived with Pirelli Cinturato P7 235/55 tyres - now set at the 36psi all round specified in the handbook. Those have always had a reputation of being harsh, but I can't do anything about that at this stage. Haven't yet found out enough about the rear air-spring set-up to know whether I can expect it to "relax" a bit as the newness wears off - or indeed whether it can be adjusted to be a bit less unforgiving. (The Spires' solution won't work for the Sportbrake) As the various forums say, it seems that Jaguar has succumbed to the current German fashion of having the suspension set very stiff, especially at the back - stiff springs, overdamped. Fine on billiard-smooth German roads, and giving undoubted improvement in ultimate cornering ability, but transmits too much vibration from poor road surfaces. A pity, as it spoils what would otherwise be a very nice car.