It's very much a personal choice, some people like the S-Line, some the Sport and some the SE and with the current A3 you can have what you like. I suggest you do a search of this 8V forum as there have already been lots of discussions and opinions expressed on this subject and it would be well worth having a read.
You will need to test drive both options as everybody's opinions will differ.
From my experience I had the lowered s-line suspension on my previous 8P and opted for the standard sports suspension on this occasion as found it just that little more softer, when discussing with the dealer he stated that he sold 4 cars with the additional lowered suspension and they have all come back regretting their decision.
Don't listen to what people here tell you. Some of them suffer from confirmation bias. You are aware there may be a comfort issue - so go and test drive a few cars.
Nearly all the reviews you will watch and read recommend deleting the sport suspension and selecting standard SE suspension.
A lot will depend on the roads you drive. We both drive on a lot rural roads. So my wife chose an SE with 16 inch alloys/tyres for extra comfort. Her new A3 is a lot quieter and a lot more comfortable than my Mk6 GTD on 17 inch tyres and sport suspension.
Probably many of these reviewers have not driven the 8V sport suspension but rather base their recommendations on the previous model where the sport suspension really was stiffer. So far, I think the 8V sports suspension is brilliant - and fairly soft. This my current opinion may change with time, but what I can conclude following 4 days of ownership. But I really agree with some other, try it yourself, if possible.
I've had S-line suspension on all of the previous Audi's and found it fine wanted it this time on the saloon but because of the 19" wheels it couldn't be done so have the sports. It's fine with sports and glad I didn't go for the S-line, but as said by others it's a personal choice and the only way to tell is try them, good luck!
We tested 2 Sportback Sports on sport suspension. In MY opinion they were firmer than my GTD. My car is fine for short journeys - or on good roads. For long journeys, on bad roads, at the end of a 12 hour day, I have to admit I bought the wrong car. I am really, really looking forward to changing it for something more comfortable - for the miles I do, on the roads I drive.
At the weekend I changed my 16 inch winter tyres with my 17 inch summer tyres. (They are Goodyear AS2s and much quieter than the original Bridgestones.) After driving for 3 hours 40 minutes today, I was thinking just how bad some of the A roads I drive on are. My car is definitely louder and firmer than a week ago. I was not planning on changing my car for a few years, but I may change next year just to get away from 17 inch tyres and sports suspension.
Mine's standard sport suspension and whilst it handles well I wish I'd gone for SE suspension. It's a lot better than my old mk5 Golf GT but still uncomfortable at times. I remember when I test drove the exact car I've got (apart from it being 3dr) I couldn't believe how good the ride was compared to the Golf.
I opted for SLine had it for a few weeks now and have to say its still very good. Roads up north are rubbish as well. Yes it does crash a little on very bad roads but coming from out civic its like an armchair in comparison so for me Im very pleased with my choice.
I test drove the diesel with sports suspension but went for the COD in the end so not sure if that makes a difference with the lighter lump up front to the suspension. I would agree the only real way would be to test drive them back to back but agree from my own experience if virtually impossible, it was hard enough tracking down a COD to test never mind once with different setups.
The car is amazing though and I think whatever you get you will be pleased.
My car is in the dealer's in a couple of weeks time and I'm going to get them to check the suspension, because it's ****** awful at the minute. I don't remember it being as bad as it was when I got it a year ago. I know the suspension can deteriorate over time, but after a year of normal driving surely not??!??