I've seen those on a couple cars and you can definately tell the difference. but like I said, once they're in and the cars sitting on them the car will drop a little more once they get past the break in period, so 1.1" could end up being 1.5+"
Are you lowering it just for looks? I'm just wondering, I like the look of a lowered stang, but if its just for looks just think of the cons as well. At stock ride height on my 95 I scrape and bottom out quite a lot around the town I live in..