I am normally very wary of guitars that don't have a truss rod because temperature changes, string tension and other factors have a way of completely screwing the action. But my Sugi DH496C freaking rocks. Great action, very playable and a beautiful neck. While I'm frightened what would happen if the neck warps, etc, I believe the guitar was designed this way because that's practically impossible if you don't do anything stupid. Reclaimed wood, so it seems really stable. It's the best guitar I've ever had for pairing with a Fishman Triple Play, I'm constantly amazed at how well it tracks. I've heard a lot about graphite necks being stable as well. Also some cheap guitars don't have truss rods. Anyone else have a no-truss-rod guitar?