B2,

Here is where people are going to get upset from me.

I sometimes use the arranger styles in professional recording. However, it depends what arranger you are talking about. You have guessed correctly that the Quality of drum samples are important. However, the way it is arranged, is also important to give you a sense of realism.

For example, Yamaha Styles are one of the best for they are well-arranged. However, they are not fit in my humble opinion for professional recording because they sound like coming from an arranger keyboard. They are good for performance but not professional recording. When you want to record a song based on a style, you want each part of the automatic style to sound as unique and distinct from other so that it gives you an impression that each track was recorded separately for the musician ear. And it sounds that it played by live musician on an real acoustic instrument for the public ear (who are not musicians.) NOT YAMAHA! but SK880 gives you this. However, Yamaha styles are better than SK880!

Let me elaborate on this by giving you an extreme example: You do not want the drums of the style to continue to play in its normal variation pattern WHILE it is playing the fill-in. Clearly, a real drummer will not do that. Now, almost all keyboards have figured out this by now.

You want each track of the auto-style to have a sense of independence of other tracks. There are so many other point of view. To my well-trained ear, I reject any recording of mine in which I detect auto-accompaniment. So you will find me, in so many sessions, deleting the auto bass track and record my own manual bass.

Some are even more senitive during performance and will play their own manual bass, like Uncle Dave does. For me, during auto-style performance, I am so busy doing other things, I do not have time for anything on the left hand other than playing the actual chord.