I'm about to order a G4 with a 13°Angled Peghead. I have a cheap Yamaha RBX bass with a similarly angled headstock and it has a string retainer to make the strings stay better in the nut(?). It could just be that that it has something to do with the nut and the Fender-style bridge of the bass (I'm putting a Schaller 463 on the G4) but I suspect that the reason for the String Retainer on my cheap Yamaha has to do with the cheap parts on it. Other RBX basses with another type of bridge doesn't have a string retainer.