I have mostly good experiences with the Bk-7m, although I haven't used it live using the arranger function very often (2-3 times). Once you have prepared your registrations and saved them in performance lists on a USB stick, it's very easy and quick to call up the performances from song to song in a live situation. What I don't like is the clickwheel you use constantly to scroll, jump from page to page and select items when you prepare things at home. I think it contributed to an RSI syndrom (tenovaginitis, "typewriter's cramp") I have in my arm.