I have owned all the grados with the exception of the 325, including the older sr100/ 200 and the hp-1. MY FAVORITES are the sr-225 and the rs-1.The older sr200 and hp-1 are wonderful sounding but they just dont fit my head comfotably. There is, however, something about the 225s balance that I just enjoy. They do seem to have the most laid back upper midrange of the current grados, and consequently seem to fatigue my ears less during long listening sessions, even factoring in the forward signature of all grado headphones. Even though I had all those other expensive and highly regarded headphones, I always found myself listening to the 225s. As for the 325s, they are the only grado I havent enjoyed, they were just to aggressive for me even for during short trials,and they were well broken in.