Brian, I love your maple. You have done some very inspiring work with it. I'm always excited to see this thread come back up with what you're doing next.
About the soil...? I have noticed that the trend these days is to stray almost, if not completely away from organic matter (as in your posts above). It makes perfect sense and I really think there are good reasons to do so. But my reservations arise because of my location. You guys have plenty of humidity and rain out there... here in WY though, humidity is virtually non-existent; in south-eastern WY we are considered "high mountain desert." -- I'm still mixing in organic matter for moisture retention (more with deciduous and barely any with pines). Would perlite be a good substitute? What would you recommend?