This is definitely one of the best investments I did on my BMW X5. Getting the rear springs in was easy on the rear, in the front it was a little tricky as the coils are very close to each other and the spring compressor that I had was a little thicker, but eventually managed to put them in.
The handling of the car improved dramatically! Of course the ride is a little stiffer, but it still is a comfortable ride. The main issue that I had before is reduce that bounce when going over bigger bumps on the road, and that's definitely fixed now.
I initially wanted to go with the 1.2" drop on the front, but I'm happy I went with the 2" drop, looks better and no issues whatsoever!