If you love to play around with your Motorola DROID RAZR M, install custom ROMs, or if you want to root your handset, the Developer Edition makes it happen. But just because Motorola is offering the phone with an unlocked bootloader doesn't mean that you won't lose your warranty if you take advantage of it. Make sure you know what you're doing because otherwise you could end up with an inoperable device. And priced at $549.99, that would be quite an expensive brick to have purchased.
source: Motorola via Phandroid