Yes you get access to BT wifi straight away, my home broadband connects me to that first then changes it to my hub, it's only a couple of mins to wait on startup much quicker than VM.
It's not the delivery that takes two weeks, they only despatch the hub & free phone when they know they can come the next day or two days time to switch it all on. My hub & phone were not dispatched until a couple of days pria switch on day. I don't know why they do this. I'm guessing because people change their minds?
Two weeks seems about right because on my screen they kept telling me they can come before my switch on date ( I waited 30 days because of VM) which the first one was around the two week mark.