O
I totally get what you are saying @Ajax123 I understand and I am pretty sure your knowledge about this subject is superior to mine, I can't say why I am not using a gypsum based adhesive......other than Mapei don't manufacture one and the last time I used a mineral one it has started to fail but that's my own fault for not using Ditra as a fail safe.
So it is as the Mapei spec at the moment
Abraided
Vacuumed
Primed
Primed
Primed again
Keraquick and latex stick Ditra down
Keraquick to stick tiles down
My supplier only stocks Mapei so going elsewhere is not something I want to do if I am being truthful.