I too think a good Leslie sound is important, even playing to people that may not be familiar with the original Hammond sound. I use organ a lot, and through the years, the comments on the sound seem proportional to the quality of the Leslie, even when the sounds are not great. There is a reason why so many took to that inimitable swirling motion in the first place, but you have to have the interaction of the drum and horns to pull it off. That is where the wannabes fail.