Yeah I see the BT function being more convenient in situations either at work or hanging out where a BT speaker is around and instead of looking stuff up on youtube I have all my favorites ready to go. So in that aspect while it wont be something I very much use, those situations I'm attempting to be more gregarious it should work out nicely.
Personally speaking I feel most already know I am quite happy with the 901s. Recently I purchased the Hifiman 700 for my son as a sort of good job for all his hard work and promise he's been showing, not honestly thinking too much of it. However, quick on function, and so far from what little I have listened to it, Its pretty solid. One thing going for it right off the back is lack of expandable storage, but barring this I would say if I were one to go to the gym more or if I jogged I would take it along as its small, light and for the price I paid has great sound and drive. It seems they are not regarded here in America much less this forum which is why I dont mind dropping my 2 cents every time I get a chance haha. I understand it seems some have had issues with product integrity/quality, however, I simply cannot relate.