Certainly think it's worth it's cost if you have G.fast, or intend to upgrade to G.fast - or apparently even if you have VDSL.
I can agree with the having G.fast or intending to upgrade to it, but that expensive a unit just for VDSL?
Had a look see at the firmware notes and its a similar broadcom chipset to the VDSL2 Zyxels, same broadcom DSL kernel driver version as the VMG3925 - d26u. Uses a different phy blob, A2pvfbH043q vs A2pv6F039x6 in the 3925, but thats to be expected considering it can do G.fast I guess. Still on the same ancient 3.4.11 kernel.
Would be nice to see some pics of its insides, but a little googling hasnt revealed any to me.
Would also be nice to see FTTC comparisons with a VMG1312 or 8x24 rather than a billion, I have a suspicion they will be very similar.