Home Hub 3 config for new Infinity install

Hi all,
Well, I've been with Demon Internet since almost day 1, way back in 1993 IIRC. However as BT have now rolled out Infinity into our village, and I can almost spit on the Infinity cab from my office window, I've decided to jump ship from Demon (bad move perhaps?)
I have quite a big internal network with several NAS, network printers and other stuff, and also use Wifi via an Apple Time Capsule/Airport Router that is connected to a Netgear router in brige mode.
I don't really want to have to fanny about reconfiguring my whole network to a new subnet, and wonder just how 'manageable' the HH3 is? Will the Openreach eng. ensure the router is configured to my requirements or just set it up as default and so long as he has a gateway connection out onto the net will just leave me to it?
Any advice, other than of course telling me that they may actually not bother to turn up at all....!

Thw Home Hub is intended to be a "plug and play" router for residential customers with no technical knowledge.
The engineer will normally go through connecting one computer to the hub to check that the connection works OK.  That's about all.
Compared with more "professional" products, there's an awful lot that can't be tweaked on the HH.  If it matters to you, you may be better off buying your own cable router.