I would say having access to the hard drive of the SD1 is the most handy feature . Another nice feature is the drum + bass feature . I have a guitar player sitting in for a MArch 15 th St.Patty's Day Gig . I di not have to rework the sequences . All I have to do is hit the "drum + bass" mode and with will take out all parts except drums + bass . Drum + Bass is now assignable to the foot switch with 4.0 !
Dano