I'm referring to the phrase "RTM candidate". But I really can't be bothed with this discussion any more. Let's wait and see whether the final release via manufacturers is identical and contains all the same bugs.
It was discussed a million times already.
The
ONLY truth is that
Windows Phone Developer Preview build is
NOT a BETA build (the opposite thing is for Windows and Xbox One Preview Program instead, with full BETA builds to test prior to RTM/Final builds releases).
In
FACT Windows Phone Developer Preview contains only the FINAL/RTM OS part of a whole GA Windows Phone Package that, when released, will contain that part (RTM) + Microsoft GA Patches for that part + OEM part (Cyan Firmware for Lumias and other firmware/drivers from other manufacturers) + Carrier part (for Branded phones at least).
Obviously and meanwhile, all the first and third party apps will be regularly updated through Windows Phone Store.
With Dev Program you can immediately obtain the first part (RTM) as soon as really finished and available, and months ahead the official worldwide release.
All the other parts (GA Patches + OEM Firmware + Carriers Customization) will be installed
ON TOP of the RTM (Dev Preview Build) as soon as they will be available too.
So the
only difference between Dev Preview and GA Release
is choosing to:
1) Install WP8.1 "in parts" as soon as they got finished: OS First + OS Patches after + OEM drivers and Carriers mods later, beginning this process months ahead the official release (April);
2) Install the whole 8.1 Package all together, but months later the official announcement of the OS (July).
The choice is yours.
And thats ALL about it, once and for good.
Have a nice day!