NZFF

Was wondering how the Real NZ addons work if they are installed with REX or do I have to choose one or the other?

Real NZ addons replace specific scenery areas with very high accuracy models of the buildings and vegetation which are actually there.
REX is an environmental addon which upgrades textures such as those used to depict clouds so they are different, but complimentary packages.

Simply adding one or the other will greatly enhance your sim and take realism to a new level

Yes, I use REX, and all my recent screenshots of Real NZ scenery include REX's features -- clouds, weather, sky and water colour etc. I'd definitely recommend an environment enhancement addon like REX to complement my scenery.

Thanks guys, looking like REX is the way to go and then add on some graphics bundles later