The PlayStation 4 may have a sales advantage over the Xbox One right now, but the battle for the living room is more of a marathon than a sprint, Head of Xbox Phil Spencer says in a new interview.

"You look at what Sony has sold, and congratulations to them; they've had a great launch," Spencer told GamesIndustry International. "Maybe we're 10 percent of the way into this generation, so we're early, early days in how this will all play out. I tip my hat to them. I think they'll likely have a great [E3], and they should; they're coming in with a lot of strength. But this is a long-term competitive space, which is good for consumers."

Both the PS4 and Xbox One launched in November 2013. Microsoft sold more than 3 million systems by the end of the year, but has not announced a new sales figure for the platform so far in 2014. Sony, on the other hand, announced in April that it had sold more than 7 million PS4 systems worldwide to date.

Also in the interview, Spencer said Microsoft's recent decision to remove the Kinect camera as a pack-in for Xbox One bundles does not mean the company is any less enthusiastic about future prospects for the technology.

"VR is an interesting technology. I don't know that it's mainstream yet, if you think about experiences in the home for consumers" -- Phil Spencer

"We see millions and millions of people using Kinect today. We've had over a billion voice commands used," Spencer said. "The use of Kinect in people's homes is incredibly high. And because people are continuing to use it, it's an area we're going to continue to invest, in terms of making the experience better."

"And I think that makes building games in that environment even better. Consumers love the device; they love the experience," he added. "They'll buy it. They'll either buy it at launch when they buy their console, or they'll be able to buy it after the $399 console; they'll pick it up and add it on later. And we'll continue to make sure that experience is great."

One area Microsoft is not likely to look at for immediate future growth is virtual reality. The VR space has gathered much attention since Facebook paid $2 billion to buy Oculus VR and Sony announced its own head-mounted display for the PS4, but Spencer questioned the technology's mainstream appeal, at least right now.

"VR is an interesting technology," Spencer said. "I don't know that it's mainstream yet, if you think about experiences in the home for consumers. But I think it's great that the game space, whether it's what Sony is doing or Oculus is doing, that so many of the innovations you see all up in consumer electronics have come out of the game space. VR is something in games and out of games. I'm watching how that evolves over the next few years."

At the Game Developers Conference in March, Spencer teased that Microsoft may be prototyping a virtual reality device of its own. "I think that technology's really interesting, and it's definitely something we've been playing with for quite a while," he said at the time.