Not sure exactly what you mean. My passengers are my 2 1/2 and 6 year old girls. OEM suspension was very comfortable. The new suspension as I mentioned is certainly more firm (for driver and passenger). However, I'm not sure anyone would really notice.
I wonder what your passengers think of the ride?
I just took a ride in the passenger seat of my 2010 GT, with stock suspension, and for some strange reason the ride felt a bit "harsher" from over there.
2013 Ford Mustang V6 with Performance Package, Recaro Cloth Seats, 19" Brembo GT Track Pack Wheels and GT Premium 19" Wheels, OEM 3:31 gears, Airaid CAI and Roush Upper and Lower Grille.