Sloping top: This is an innovation of the late Thomas Humphrey. The idea is to increase the string angle to the bridge which in turn will increase the string's power to the top.

 

Cantilevered Fingerboard: The fingerboard extension does not touch the soundboard. This allows the entire top to resonate 

Adjustable Neck: just pop out the strap pin and you can change the neck angle, i.e. the string action, with a turn of an allen wrench.

Access Door: so you can get inside for neck adjustments, pickup installations, or any other reasons you might need to get inside your guitar.