I have been using the MA900s since they came out. I like them a lot and think they are an excellent value. I use them at my office where I need cans with minimal isolation in order to hear door knocks. I have cycled through a lot of different headphones for this role and until the MA900s, had settled on the F1s. I really like the F1s but feel the MA900s are a notch superior in terms of sound quality. They just sound cleaner- better focus and clarity. More present bass. The soundstage is excellent but I slightly prefer the F1s for that.   I find...