A8 D3 SE or Sport
 

is the SE on 18s more comfortable that a sport on 19s ? Preferences on the sport Vs comfort seats ?

I drive both an SE and a Sport regularly - the SE is on either 20" FE wheels for summer or 19" D4 wheels for winter, the Sport is on FE 20" all the time.
Comfort wise a lot of it depends on the profile of the tyre rather than the diameter of the wheel but spec wise the SE has got 20mm more of height and bounce so it does feel more comfortable especially on the motorway.

The sports seats are more supportive and hold you in when you are pressing on and on an A road etc, but for all round comfort the comfort seats for me are pretty good and easy to get comfortable in etc. +++

thats what i think. I have driven a 09 LWB SE for a while on 18s with comfort seats and this side of a RR or Bently its hard to better. Think the sport of 19s with he recaro style seat will be slightly harder... hmm... Looks vs comfort.

The thing I notice is how many customers fall asleep on their journeys and it's quite a high percentage lol another CEO fell asleep today in mine coming back from the airport this morning!

Don't forget you can still run the SE in dynamic mode when you want, and in my case I have a sports steering wheel, but I prefer the comfort seats on 8/10 trips