I've done Firm Feel suspension going on 10 years now. Mostly A body with a few 71 B bodies. My 71 RR has a complete Firm Feel suspension and it's like riding a roller skate.

For the street and a occassional autox or road race that's the way to go. If you want the full adjustability to fine tune and adjust based on track conditions then Hotchkis. I've never owned a car with their product however I have ridden and driven cars running the Hotchkis system. I think the two are comparable however a lot of R&D goes into Hotchkis. Firm Feel's experience with their systems has been mainly customer improvement suggestions from actual track time. Not sure on the R&D. You may want to talk with Dick at Firm Feel.