When I used b&w's I used to listen at much higher levels than I currently listen with my JmLabs. When listening to Pop and rock I usually listen between 75-85 db currently. However before I used to usually listen around 85-90 db...I guess that is what it took to make me feel like I was getting a good soundstage with the b&w's.
However, sometimes when listening to a great classical symphony before and now with my JmLabs, I let the volume get the best of me. I usually listen to orchestral peaks around 100-103 db. There is something about the power of an orchestra that makes me do this...plus when you are in front of an orchestra or in a rehearsal hall, these are about the spl's of the ensemble anyway. In rehearsal for the Austin Lyric Opera, I have seen/heard/experienced bass drum hits around 107 db, as well as cymbals crashing around 110 db. Plus there is nothing really as great as listing to a good brass section, especially when you can image out the insturments!
Good time, great hobby!
Peace,
Ben