UPDATES
Virgin do update equipment during the night time, so if switched off at night then udates can be missed on the hub and tv box.
The same applies is equipment is switched off during daytime.
That is why the general virgin advice is to leave equipment on 24/7.
Also thing like printers, hub connected phones, or IOT devices will not work if the hub is swtched off.
I do switch off my hub but often miss a V6 tv box udate which can result in losing the electronic programme guide EPG.
It happened to me today and upset my preset recording, so a 1 hour recording was wrongly recorded for 2.5 hours.
The hub connection to the tv box via wifi or cable is needed for the apps, catchup, EPG, updates etc, but if it does miss an update the tv channels do still work but other services may not.
This is easily rectified with a manual update in the V6 settings-network and check last update, if it failed click connect to virgin and it updates in approx 5 minutes. The V6 tv box update occur at preset times, and if one is missed it does not auto update, so it has to wait for the next update unless connect to virign is selected and that does an instant update.
The hub udates each time it is rebooted when switched back on, so usually no problem.
The answer is not clear, leaving switched on is more reliable and the cost saving by switching of at night is probably small approx £10 per year.
Similar savings could be made if the tv box is switched off at night.
On balance 24/7 operation is not expensive and most people probably leave them on, I often use my computer during the night myself so switching off can be a nuisance, unless this is done for some preffered reasons, I do switch off when not in use and I have my own reasons do to that, but I have not got the hub connected phone yet and prefer the landline phone.
If equipment is switched off, such as hub and computers when not in use, there is less chance of hacking so that improves security, and cybercrime and hacking does happen on the www internet, I have had it myself.
alf28