I would stick to a hammond because it is the real thing. i have heard the diversi organ and dont get me wrong, it sounds exactly like a b3 but it lacks certain elements that make it like a b3. i seen a video where an organist (forgot his name) did a clinic at berkelee and he was playing a diversi. while he was playing, he turned the organ down using the volume pedal and you couldn't hear anything. if you did that on a b3, you would at lease hear something.