I used 3" drop springs from them. Even after settling they didnt come near what they advertised. I only got maybe 1" from them, and you could only notice it when you measure.
I've read some people have used them alright, but I dont like them. I'd get Belltech or DJM. I think all drop coils wont give advertised drop everytime though. At least in my experiences (3 seperate brands, on 3 vehicles, none of which gave advertised drop).
i got a 3/4 drop from them off ebay; blocks, shocks, and coils; the rear shocks were hard as $hit and it rode like a brick, so i threw the stock shocks back on, but the fronts rode fine. The coils only dropped it like an 1.5", so i ended up putting a set of spindles on(not spring tech). and the coils ride decent enuff.