That's not to say he wasn't a little nervous about the reaction from staff and clients who felt good about the company's separate identity.
"I don't know why we worried so much about changing," he says now.
"It was an easy decision to do the Gen-i thing, go from Gen-i to Spark Digital, it was an easy decision but I worried about how some of the people would take it.
"I don't know why I worried so much, people have gone for it."
Telecom was one of New Zealand's most recognisable brands and on one level it was a huge call, says Miles, but the 27-year-old brand, which stood for a legacy of landline voice calls, had had its day.
"Because the name Telecom, it doesn't reflect cloud, it doesn't reflect Lightbox, it doesn't reflect optical transport, it doesn't reflect the mobility story we have, it doesn't reflect those capabilities and it just can't be made to do that."
Times had changed and it was those changes that had attracted Miles, a veteran of the tech and telecommunications sector, including leading competitor Vodafone here and in Britain, to the Gen-i job early last year.
He says with the network business Chorus stripped out, there was an opportunity to be a part of creating a very different organisation from the one he'd spent years competing against.
About 15 months ago the Telecom leadership team he was part of made two decisions. The first was to stand for New Zealand.
"It may sound trite but it's not, it's very important." Miles says the best and worst thing about New Zealand is its distance from the rest of the world.
"It seems to me the sort of thing we do helps bring New Zealanders closer to each other and it also helps connect New Zealand to the world and the world to our country.
"There are very few organisations out there that have got the scale and the resources to be able to make a real difference in this and this is one of them." The focus on New Zealand has seen Spark sell its Australian business AAPT and exit its stake in Cook Islands Telecom.
The second decision was to stand for digital, says Miles. In all his discussions with customers since the global financial crisis, they had been asking how they could change their businesses more quickly, he says.
Spark Digital, for its part, has spent millions boosting its data centre capability and buying cloud service providers Revera and Appserv.
"We don't have all the answers," says Miles.
"Our customers know more about their business than we do but our job, as we see it, is to know enough about our clients' business to be able to put forward ideas to them about how they could do various things and obviously for us to have the right level of capabilities here, that when our customers are ready they can take advantage of those."
That has also meant a lot of change within Spark Digital, resulting in many people moving on, says Miles. "Some of that has been about, frankly, to start with we just had too many people." And some people were doing things of little or no value to customers.
He says the organisation had a lot of capability but it "was like walking through treacle to get things done".
"A big part of what we've done is trying to speed things up."
Miles had a unique view of Gen-i, having been a customer as head of rural service firm PGG Wrightson.
He says in that time he'd had some big opportunities in his business that needed a technology boost, but Gen-i wasn't on the front foot with solutions.
"As I went round I gave a not particularly flattering view of where we were at. I wasn't delivering a very popular message." His honesty about the shape of the business got a range of responses, from people shuffling their feet to several admitting to being grateful to hear the truth, he says.
"I think it is very important to be authentic, and by that I mean I don't do the corporate thing, I just tell people how I see it."
He admits the changes over the first nine months of his tenure were done with a "fairly blunt instrument", but the result has been a shift within the organisation that customers are starting to see.
"It feels like we're getting a whole lot more right than not, but [there's] a way to go." Managing change is having the skills to move the business forward, he says, and the right people today may be different to the right people in three years' time.
