My thoughts having just upgraded to BT Infiniity 1 recently and needing vdsl kit. I can't be certain over the performance of the Asus dsl-ac68, but the number of reviews criticising the modem was enough to convince me not to buy. I ended up going for a separate modem and router combo, with a HG612 modem I picked up for a sensible price off eBay (now unlocked with the help and Howlingwolf's firmware on this forum) and the Asus RT-ac68u (router only version). I'm now a convert to the flexibility of having these separate, and being able to reboot the router without disconnects is a major plus (if you or the boss can live with the extra box and wiring, happily my better half was fine with it).
The Asus router has been rock solid so far, and is also very easy to get custom firmware on it. Still early days as only had the Asus up and running for a few weeks, but with the Merlin custom fw on it I have all the functionality I need. It has improved wireless range in my house dramatically with no drop outs (HH5 would frequently drop 5ghz on our droid phones), and the adaptive QoS seems to work well for prioritising Netflix/Amazon streaming. Don't use voip though and of course wireless performance will differ, but I wouldn't hesitate to recommend the Asus router. I have a NAS, homeplug circuit, Vodafone suresignal hooked up plus lan link back to the modem which takes up the 4 Ethernet ports but a switch would give you more if need be.
My only issue with this setup is now worrying about my line stats but that's for another thread!
I'm on the phone atm, so having to "fly-by-tapatalk"