TEIN is very good. They control the majority of the aftermarket suspension industry in Japan, about 90% since its the only product they make, and are OE suppliers for many Group-N (showroom-based cars) teams in the WRC and Asia Pacific Rally Championship.

I've tried the TEIN HA, and the riding comfort is actually pretty good. This is the entry-level coil-over.

Another benefit is that ALL TEIN models are supposedly rebuildable, something the other Japanese coil-over companies don't offer in their coil-overs.

I'll be able to try a TEIN RA soon, its meant for entry-level racing.

IMHO if you don't plan to race or use the car occasionally on the track, coil-overs are overkill.