I have a RAZR M that I still love. I was able to unlock the bootloader before the Moto update that undid it.
Issue is that this phone will shutdown or freeze occasionally (about once per day) when not used for long periods. Especially annoying when I'm expecting an alarm in the morning.
So I can't update it to, perhaps fix the issue; I have put various ROMS on it so that didn't solve the issue.
I'd love to get a Developer edition, with an easily unlockable boot loader; but have been unable to source one. On eBay, every posting I've seen listing Developer Editions has been incorrect. They posted the wrong specs.