While frequency response is just one aspect of sound quality, I found David's observation interesting. I had SR225 for a short time (liked the sound but not the discomfort), so I guess the tonal balance of the higher Grado's would be similar, even if they probably do a better job of resolving, etc. It should be noted that frequency response graphs are logarithmic so the absolute differences are larger than they appear (but then there is the ear's ability to resolve differences). On the other hand the similarity of the shapes of the curves is telling.
I do find that there is way too much uncivil discourse on these forums. I don't understand the regular angry responses. This is a hobby. Everyone has their own view. Some people spend way too much time hobbying and bantering in the forums and have learned a lot and have developed their ears and audio knowledge. Other people, just as earnest, spend a lot of time at productive things and haven't had as much time to be experts in this hobby. A simple observation and question shouldn't incite an angry response. If it is deemed naive, one could constructively explain why, in a friendly tone. Alternatively, ignore it and go on to a more interesting thread.