Maybe I should have clarified a bit but Contouraholic was right - a high pressure gas strut like a Bilstein will raise the effective spring rate just a bit - enough to raise the ride height. It's basicly pushing back against the car's weight, helping the spring carry the load.
Extended free length of the strut has nothing to do with ride height. Once a load is placed on the spring/strut combo the only thing determining ride height is going to be the effective spring rate. I'm sure the Bilstein's 1" shorter damper shaft length is moot when loaded with vehicle weight. We don't go driving around at max travel now do we. If we did jacking our cars up would be a breeze as there would be no sag travel to work thru before the wheel left the ground.
If we were talking about total droop travel, the Bilstein would have less than the stock struts. This may help keep shorter than stock free length springs (like the BAT ones) from rattling when going thru a big dip in the road, but will not effect how much travel the car has from it's standard ride height before bottoming out. A shorter damper body does that.
As I mentioned before it's common knowledge in the VW world (where Bilsteins are widely used and have been for years) that they can raise the ride height a bit when compared to low pressure units like the stock SVT struts.
)