Collected my SEL 2009 model on Saturday, trading in a year old SE (both autos), so been driving around for a couple of days on all kinds of roads. Not sure whether the improvement is a reflection of the model upgrade or the revisions but couldn't be happier! Styling differences are pretty subtle - new design wheels and rear lights , indicators in mirrors, stitching on seats, controls on door panels, front grill which now has more chrome surround and wider 'slats', and a slightly darker dashboard, with chrome added to the MM surround and DVD input, its also now more black than the previous grey and looks much classier. What put me off the SEL previously was the tacky looking wood finish but now it's a really smart looking birds eye maple gray, which looks great! Sat nav itself (software) really doesnt seem to have changed other than some features can now be operated whilst driving, as can the bluetooth phone. Reception on the phone is also improved, apparently, the sun screen now kills ambient noise, and it does seem to work! Where the car is really improved is the handling - one of my main concerns with the SE was that it veered all over the road, especially at speed and braking but that's now banished with the new model. Am sure the 18 inch wheels (as opposed to my old 17 inch ones) help, but I think it's far more than this - it doesn't just grip the road better, it actually steers in a straight line at all times, even when braking!! My other bugbear with the previous car was the awful headlights but the HIDs are such an improvement, literally like 'night and day'!
Anyone considering a new car - buy the IS. As for the model, it's a no brainer - the SEL with MM, albeit its now only available as an auto, but the auto was always the better option. The extras over the SEI are well worth the price difference. BTW , anyone thinking 18inch wheels equals a less comfortable ride, they don't!