As a self-confessed Xbox fanboi...
I think it's pretty clear why PS4 sales have smashed the Xbox One - Microsoft screwed up their PR from day "One".
Hardware specs are irrelevant and are willy-waving bragging rights of idiots. It's always been the killer app that decides which console reigns supreme - look at the Wii as a prime example, but marketing is a close second. Inferior graphics (compared to the same generation offerings by Sony and Microsoft) and a suite of launch titles more suited to younger gamers than the 16-35 customer base we're told are the core gamers. Yet the Wii had the killer app of a new interface that anyone in the family could pick up and use. I'm sure many are familiar with suffering from elbow-ache on Boxing Day after an endurance session of Wii Sports Bowling.
So why hasn't the Xbox One with it's more advanced Kinect 2.0 interface done the same? Because Microsoft presumed this and their One-box-to-rule-them-all approach would be as popular with punters as it was in the boardroom.
Fail #1.
The big reveal was so focused on SPORTS SPORTS SPORTS that they ignored that the rest of the world are a little bit more relaxed when it comes to viewing sporting events. Personally I would much rather watch an hour of Charlotte Dujardin putting Valegro through it's paces (dance pony, dance!) but I digress...
Fail #2.
A major criticism of the Xbox launch was the scant mention of the console as a gaming platform. We all know the price of the basic Xbox One is more than the PS4 (and I know several PS4 owners who have spent far in excess of the equivalent Xbox One on their PS4 bundles) but perhaps Microsoft should have taken a bigger hit on the cost and subsidised the Kinect 2.0 camera to bring it more in line with the PS4. I'm sure Microsoft would have clawed back the cost within a year of flogging Xbox Live subscriptions and DLC.
Fail #3.
The always-on Internet and Kinect spying debacle was a PR shit storm in a tea cup. The UK's broadband offering is abysmal with only the select few being able to enjoy reliable, fast Internet. To make such a mainstream device so reliant on having an Internet connection - even if it's technically feasible isn't going to win any favours, especially with paranoia over the NSA's desire to watch you sitting in your underwear whilst playing on Call of Duty.
Fail #4.
Underestimating the second-hand games market. Not only did Microsoft upset the consumers that enjoy picking up a bargain game a few weeks after launch, or trading in their unwanted titles for a few coins but they also angered retailers, some of which would have a big part of their business model jeopardised by taking away used games. For these retailers it's bad enough that this generation of consoles will see downloadable games become the norm thus taking them out of the equation but they wouldn't even have the used games to fall back on. Turtle Beach headsets and Pokemon cards a business model does not make.
So armed with these and I'm sure more (but I've typed too much and I'm losing the will to live) criticisms in their utility belts it's very easy to see why Sony have taken this early lead in the run up to Christmas.
I am one of those that will wait it out and see which console piques my interest enough in a few months time, after the initial hype machines have been wound-down, day one bugs patched and the RRPs have been slashed. But by then it may be a one-horse race with my friends already adopting one console over the other, almost forcing me in a particular direction or face playing online against sweary American children.