I'm using RSX-S D2's got them for $800 shipped new. Using 9kg fronts and custom 20kg rear springs that I ordered from D2 USA.
Love them, I thought going cheap on coils would be disaster but so far it hasn't. I actively autocross and this setup I have is boss.
My ride height is ~0.5" lower than stock but I also have other suspension mods:
DC5-R aluminium front LCA's
Buddy Club extended ball joints
T1R inverted tie rod ends for DC5-S
Adjusted the ride height on these coils is very easy to do and straight forward. Also, HIGHLY RECOMMEND you grease the spring perches and the pillow ball upper strut mount (if you get the pillow ball). You will not get coil bind noise if you actively grease them or clunking sounds either from the mounts.