It's all one; meaning 1964 is just among the blend going into the unnamed hybrid emulator. It's just mentioned so much, because of the 1964 update (.99 beta) on the way. That upcoming update is important, because we're hoping all the improvements that come from .99 beta will someday be included into the hybrid emulator.
At least that's my understanding. I'm very sure it's correct.
-Bender