OK, so I've got a nice approval rating going with Zero-G Sports Arenas built as required (+55% morale).

Researched VR Centres and all the ZGs were set to auto-upgrade to VRCs..... which only appear to carry a +40% morale bonus? So the "upgrade" is actually a 15% downgrade.

I'm sure this is just a simple fix, and not that much of a problem now that I know to never bother researching VRCs.

Cheers all!