Digital Voice will give you the same reliability, trust and familiarity of your current home phone service
Which is literally impossible to promise and a lie. For a lot of people, just plugging a wired phone into the socket and knowing it will work, even during a power cut, is a big deal. Digital Voice does not offer this, so how can they claim its the same reliability and familiarity as their current home phone service?
I'd also argue that Internet problems happen far more than physical line problems for most people, again a hit on the reliability.
No matter the benefits, glossing over the huge increase in pitfalls is not good.
I also think its going to be a hard sell unless they drop call charges to be competitive with mobile. If I could call at the same price on my landline as O2 and Three charge, I would have used it a LOT more as the call quality is so much better. If my landline will effectively be using my mobile (because why on earth bother having a home phone at all once its VoIP), then this becomes even more relevant.