Slow UI on the Hub 3.0 is a known issue that has been fixed in a later firmware release. No release date yet from VM for the updated firmware.
Disclaimer - I don't work for Virgin Media. I'm just another VM user trying to help out so my answers may be wrong :-) If you do like my answer please mark it as helpful as it may help others My setup: Vivid 200 Optical fibre with Superhub 2 in modem mode connected to a Netgear R7000 router. Telewest/VM user since 2001.