I guess that Hardiman the Fiddler should respond to "hardiman the difficult." I agree that 9/8 time is difficult, which is why I jokingly told someone the other day, it helps to be drunk! I do best with 9/8 time if I think of the piece like a waltz with triplits. Especially when practicing, I put a little emphasis on the first of the notes and hit the other two more lightly.
I had someone advise me once that you can sometimes adapt and edit tunes to make them more playable. Sometimes it helps to leave out a note or two of someone's arrangement---after all aren't we trying to play our own arrangement of the piece. I agree with Les B's advice about practice too. Even after I've learned to play something up tempo, I will often come back, play it slow, pay attention to the bowing, and fingering, to relearn it. Hardiman the Fiddler