I asked chat why the 3 and was told if I went ahead with the order I could request a HUB 5 once I had it set up - this would be FOC. I said I'd heard bad things about trying to contact Virgin (Now is rapidly catching up!) so would prefer if I could have the HUB 5 at the get go. No, I was told but they could provide the HUB 4. Being usually a laid back type of person I agreed but when it came to confirming the order I was told it would be a HUB 3!!! I'd get and NOT a HUB 4 until I was signed up and then I could request a more update to HUB.
Any promise of a Hub 5 being FOC and on-request is being made purely to secure a sale, there's little chance that it will be honoured anytime soon. More than a few new customers here are complaining how they were made similar promises, only to find out later that they'd get whatever hub VM chose to give them, like it or not. The wifi from all VM hubs is pretty mediocre, but if you've got a competent mesh system then use that and keep whatever hub they offer in modem mode.
If you're speed restricted on an Openreach connection, VM can be a good choice, but in addition to my comments about the hub and other members advice on customer service standards, you should also be aware that any VM installation date you get even in writing is only a guess - many customers get connected on time, some have to wait many months. And finally, VM have announced big price rises - if you order today you'd see a big increase in your bill in a couple of months, and because new customer pricing is heavily discounted, and the price rise is calculated on the undiscounted price, the proportionate increase you'd see may well be in the 20-30% range. Obviously you'll have incoming price rises with your current ISP, but just don't bank on the VM advertised offers being fixed price, because they are not.