Totally Confused with All the Builds

[WireX]

The builds they are releasing aren't numbered by them, they are based off build numbers from the sources of the roms:

21501 to the 21800 series releases (219** today): From microsoft's builds, less customized, more of a pure 6.5 build, depending on what the chef adds
2300*: HTC's modified 6.5 builds