I have had AD08's, PS2's, and PSS and I can say from experience that the AD08's are the loudest of the bunch. Grip is great but they get loud as they wear.
'08 E90 M3 - Alpine White - Sold
'13 E92 M3 - Silverstone II - Sold
'04 E46 M3 - Jet Black - BBS E88, KW Clubsports, Brembo BBK, SuperSprint Exhaust, Recaro
'15 i3 - Laurel Gray - Why would I mod this thing?