It's a question that comes up a lot. If you do a few searches (using the google search tool in the Water Cooler, you'll find a fair amount of discussion on it, both positive and negative. Short story, Ian was experimenting with the VP150 config, and this one sounded really good. The phasing may be an issue with pink noise, Alan says, but it's not evident with actual material.

I am the Doctor, and THIS... is my SPOON!