The standard tires are 205/60R16, and compared with my previous Pontiac Grand Prix GT, which as 225's, I'm pretty sure I can feel the difference. Granted, it's a different car, sits a little higher, just a tiny bit narrower (as I recall) ... but I still miss the grip.
The owner's manual says that altering the slightest specification about anything will bring certain destruction upon the vehicle. It claimes the TCS system, for example, depends on nothing changing.
But a car-aficionado friend of mine says - with no more of a reference than "I've read the magazines a lot and you hear it all the time" - that "Hondas" are meant to be modified, and that's the reason a lot of people choose that brand over some other.
And, the 2003 S-Type sported 215's - I would guess that the frames and suspensions, etc., are about the same.
So - what about getting wider tires when it's time to replace them?