UPDATE:
I've compiled the information in this thread into this table:

OEM ground clearance* with D3 at rest or when traveling below 75mph
Clearance*-Level Mode---Suspension type
100 mm-----dynamic------sport A8/A8L, S8
100 mm-----dynamic------non-sport A8/A8L, W12
100 mm-----automatic----sport A8/A8L, S8
120 mm-----automatic----non-sport A8/A8L, W12
100 mm-----comfort------sport A8/A8L, S8
120 mm-----comfort------non-sport A8/A8L, W12
125 mm**---lift---------sport A8/A8L, S8
145 mm**---lift---------non-sport A8/A8L, W12

OEM ground clearance* with D3 after traveling 75+ mph for at least 30 seconds but at no time falling below 44 mph for more than 120 seconds or below 22 mph for any period of time.
Clearance*-Level Mode---Suspension type
95 mm------dynamic------sport A8/A8L, S8
95 mm------dynamic------non-sport A8/A8L, W12
95 mm------automatic----sport A8/A8L, S8
115 mm-----automatic----non-sport A8/A8L, W12
100 mm-----comfort------sport A8/A8L, S8
120 mm-----comfort------non-sport A8/A8L, W12
N/A**------lift---------sport A8/A8L, S8
N/A**------lift---------non-sport A8/A8L, W12

*Ground clearance figures sourced from a US 2008 Audi A8 manual
**(lift mode can be activated at speeds up to 50mph, goes back to previously set mode at 62+ mph)


VAG-COM/VCDS level adjustment adaptation can theoretically lower your default ride height by up to 25 mm although adaptation might not take at 25mm (it would not for me) so your lowering may be limited to 20mm or less.

Here are the minimum theoretical ride heights with maximum 25mm VAG-COM/VCDS lowering:

VAG-COM/VCDS modified ground clearance* with D3 at rest or when traveling below 75mph
Clearance--Level Mode---Suspension type
75 mm------dynamic------sport A8/A8L, S8
75 mm------dynamic------non-sport A8/A8L, W12
75 mm------automatic----sport A8/A8L, S8
95 mm------automatic----non-sport A8/A8L, W12
75 mm------comfort------sport A8/A8L, S8
95 mm------comfort------non-sport A8/A8L, W12
100 mm**---lift---------sport A8/A8L, S8
120 mm**---lift---------non-sport A8/A8L, W12

VAG-COM/VCDS modified ground clearance* with D3 after traveling 75+ mph for at least 30 seconds but at no time falling below 44 mph for more than 120 seconds or below 22 mph for any period of time.
Clearance--Level Mode---Suspension type
70 mm------dynamic------sport A8/A8L, S8
70 mm------dynamic------non-sport A8/A8L, W12
70 mm------automatic----sport A8/A8L, S8
90 mm------automatic----non-sport A8/A8L, W12
75 mm------comfort------sport A8/A8L, S8
95 mm------comfort------non-sport A8/A8L, W12
N/A**------lift---------sport A8/A8L, S8
N/A**------lift---------non-sport A8/A8L, W12

**(lift mode can be activated at speeds up to 50mph, goes back to previously set mode at 62+ mph)



ORIGINAL POST:
I was looking up the automatic speed based lowering for the various adaptive air suspension modes to update a post in another thread and discovered something that is news to me. I've know that the default ride height for sport suspension is 20mm lower than standard suspensions and I always assumed (and never saw stated otherwise in any online source) that the speed based mode adjustments carry over exactly from the Standard suspension.

But that is not the case per the the adaptive air suspension section in the Audi A8 manual.

As most in the D3 section already know, here are the default ride heights for standard and sport suspensions on D3's:
Audi A8 (4E) standard suspension (PR-1BK): 416 mm (front) and 398 mm (rear)
Audi A8/S8 (4E) sport suspension (PR-2MA/2MB): 396 mm (front) and 378 mm (rear)

What's interesting and news to me is that for sport suspensions, dynamic mode doesn't drop the car an additional 20mm like it does with the standard suspension. Sport just means that comfort and automatic modes ride at dynamic mode height. The damping and the other characteristics are altered between these mode but not ride height.

Furthermore, when above 75mph for more than 30 seconds, standard suspensions drop 25mm in automatic mode and 5mm in dynamic mode, for a net 25mm, but sport suspensions only drop 5mm in these mode, also for a net of 25mm vs standard suspension comfort mode. Both suspension types yield the same absolute minimum ride height.

Also, lift mode is 20mm lower for sport suspensions than with a standard suspension.

All things considered, it seems that standard suspension is more versatile. I am aware that sport suspensions have stronger sway bars and S8's even more so. I wonder though if the air shocks are different between standard/sport/S8 suspensions and if so how this affects the suspension characteristics.

I've attached photos of the two pages in the manual that discuss the modes, mode based suspension characteristics, and speed based lowering/raising.

 

You are right. Actually Sport suspension has firm and soft Dynamic and 1" lower Lift mode. I don't like stronger sway bars eater. You sway them once a week and they are spoiling your comfort all the time.

I don't know if VCDS lowering is same. Probably yes.

I do not think there are other differences. Shocks are very firm in Dynamic mode. Any firmer would have sense only on a track.

 

You have it right on sport vs. non-sport as far as versatility--once you know about the VAG COM option to get baseline ride height to where you like the look vs. ride vs. ground clearance compromises, non sport gives you more total range of adjustment.

On the air shocks, yes at the part number level they are different. Using the conventional steel spring C5 I have as an example, Audi would typically say the spring rate was something like 30% stiffer. Also needed since when they drop the ride height they have less total range of motion in which to absorb big hits before it bottoms out.

On the sway bars: if you have seen my old posts on this (or follow via the auto sig. links), turns out the W12 is an odd hybrid. It has non-sport air shocks, but it has Sport suspension sway bars, both front and rear. I found this when I confirmed the part numbers and diameters on the way to swapping out my W12 bars to the S8 level. I did it intentionally, knowing it would stiffen the ride a bit (offsetting some of the non-sport air shocks), plus improve cornering at the margin. CovertW12 (in Florida) followed my lead and likewise said he liked it; he has since sold it and moved back to an RS6 as his personal favorite. In general, the bar change is subtle rather than dramatic. The factory bars are relatively inexpensive, less for example than H-Sport bars popular on other Audi models where they are available.