Hi I have upgraded to smart hub 2 and have premium whole home discs also..
should I stop using the whole home discs and just use the smart hub and smart disc?
There is no need to change, just continue using the whole home discs, with one of them connected to an Ethernet port on the home hub, just as before. It would be better to turn off the wifi on the new hub, just as you must have done on the old hub. That should avoid any possible wireless channel conflict.
The two systems are incompatible, so you can only use one or the other.