I bought them for the same reason you did...even tho i have not put them on yet im 99.9% sure that i will be happy. Only thing i have read is that it takes a few weeks for them to fully "drop" to the 1 and 1.25 drop.
my roommate went from eibach sportlines to frpp B springs and loves it. The sportlines are too low for our area, and the b springs are about the same drop as my pro-kit, but more of a stiff spring. My car bounces over speed bumps when just creeping, and his is very stiff and smooth