Hi, i have an Xbone connected to my Super Hub with an ethernet cable and experience very very poor download speeds.
On my pc in the other room that uses wireless i can download at 3-3.5MB/sec fairly consistently whereas my Xbone gets maybe 100-200k/s. Given the size of modern games and DLC this is pretty crap
The issue isn't a duff Xbox either as i've just swapped my original Xbone with a One S and have the same problem. I don't think I ever had this problem with one of the older black Superhubs last year, it's only started since i moved house and got one of the white ones.
When you swapped consoles did you use the same Ethernet cable? If so it might be worth trying a different cable to rule out a faulty cable.
Is the Ethernet connection direct to the hub or via any third party hardware? e.g. Powerline adapters or a switch.
Have you tried connecting the Xbox via wireless to see if the speed is the same?
You could try putting the hub into modem mode to see if it makes any difference.
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 my answer solves your problem 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.