These springs dropped my car exactly the right height. They were not too bad to install by following the famous TacoBill's DIY on the Mustang Source Forum.
My car now looks very aggressive with these springs combined with my staggered Shelby Razor wheels/tire combo!
The springs lowered the car just enough. Getting rid of that huge factory gap and giving it a more sporty look. The car handles much better. I kept the factory struts without camber bolts or plates and have not had any alignment problem. The springs are great for anyone looking to get rid of that ugly gap.
These lowering springs completely changed the look of my car (2011 Mustang GT w/ Brembo kit). The stance is properly aggressive without being slammed to the ground. Brake dive and throttle lift is completely eliminated.
I did run into some suspension geometry issues after installing these springs: the wheel-hop problem that always exists in stock Mustangs was made much worse. My correction for that was to install Lower Control Arm Relocation Brackets from BMR, and problem solved.
They were a tad bouncy with the stock struts and shocks, I solved that by getting a set of Bilsteins to replace them.
Overall, a great buy!