This was no surprise as a follow-up to the Surface Pro 3 has been rumoured for a while, but Microsoft did unveil a wealth of hardware upgrades that, even at this early stage, should give Apple cause for concern.
The Surface Pro 4 is the series' slimmest model yet at 292x201x8.4mm. That's still not quite as razor-thin as the 6.9mm iPad Pro, but the Surface Pro 4's slim bezels make it a solid 13mm shorter in length and 9mm shorter in width, even with a comparable display size.
The iPad Pro is also lighter, at 713g-723g to the Surface Pro 4's 766g-786g, although again the latter remains an improvement on the Surface Pro 3.
Despite slimming down, the Surface Pro 4 keeps one of the Surface line's killer features: a full-size USB 3.0 port. Very, very few tablets include this versatile and widely used connector, so the Surface Pro 4 will have a big advantage for enterprise users as soon as it's released.
One small but potentially very useful addition is a magnetic clip on the tablet's side, to which the new Surface Pen can attach. On previous Surface Pros, the pen was carried loose or slotted into the expensive Type Cover attachment, so this kind of integrated storage is a very welcome little feature.
Microsoft has bumped up the Surface Pro 4's display in size and resolution, and it's now a 12.3in screen at 2736x1824, or 267ppi. That's not quite as many pixels as the iPad Pro boasts, but the two devices are almost identical in density: 267ppi versus 264ppi on the iPad Pro. We'd therefore expect both slates to look similarly sharp, and with Apple's effort gaining only an extra 0.6in of diagonal space, there won't be much difference in what can fit on-screen either.
One of the most attractive things about owning a Surface Pro, from a business standpoint at least, was that they ran full-fat Windows operating systems, and the Surface Pro 4 is no exception. It will launch with Windows 10 pre-installed, which makes perfect sense. The Continuum UI, which can switch between a traditional desktop view and a more touch-optimised, Windows 8-style tablet mode, is perfect for 2-in-1 devices like the Surface Pro 4. The only downside is that this will require the purchase of a Type Cover.
Plus, Windows' vast compatibility with uncountable pieces of productivity software makes it theoretically superior, in an enterprise context, to the unproven iOS 9 running the iPad Pro. The latter might be fine on iPhones or consumer iPads, but it's not hard to see why a proper desktop OS might prove more appealing than a mobile OS for getting serious work done.
Microsoft's Panos Panay claimed during the unveiling that the Surface Pro 4 would be 30 percent faster than the Surface Pro 3 and 50 percent faster than the MacBook Air. That's a bit of a wonky claim, as the Surface Pro 4 can, like the Surface Pro 3, be fitted with one of a range of processors.
That said, these chips aren't creaking old silicon; they're all from Intel's newest, 6th-generation Skylake family, starting from the Intel Core M3 and scaling up to the Core i5 and Core i7 series. The latter two in particular are desktop-grade chips and, paired with up to 8GB of RAM for the i5 and 16GB of RAM for the i7, we'd be shocked if they delivered anything other than top-tier performance.
It's also worth noting that all Surface Pro 4 models will include a Trusted Platform Module microprocessor to prevent unauthorised hardware tampering.
Let's be honest: cameras aren't the headline feature on something like the Surface Pro 4. Even so, they sound very decent by tablet standards: an 8MP rear-facing camera with 1080p video capability, plus a front-facing 5MP for video conferencing.
What's really interesting is not the cameras themselves, but the functionality they enable. Windows Hello, a face-detecting authentication tool added to Windows 10, makes it possible to sign into the Surface Pro 4 simply by gurning at the front camera.
There's been no word on specific capacity, but Microsoft said that the Surface Pro 4 can endure up to nine hours of video playback. That's not quite on par with the 10 hours supposedly offered by the iPad Pro, so that might give the Apple slate a few bonus points in the eyes of road warriors, along with its lower weight and slimmer profile.
Nonetheless, nine hours is still enough to make it through a working day without needing to reach for the charging cable. It's not an outstanding battery life, but it meets our expectations for a Surface Pro.
Incredibly for a tablet, at least one configuration of the Surface Pro 4 will include a colossal 1TB of storage, although Microsoft hasn't revealed pricing for this premium option.
Right now, models with 128GB, 256GB and 512GB solid state drives have all been confirmed. They all match, or absolutely crush, the 128GB and 32GB options of the iPad Pro, a big win for Microsoft, particularly since users in the design, manufacturing and creative industries will want as much integrated storage as possible. What's more, a microSD card means that the Surface Pro 4 can be expanded with as much storage as users can afford.
One of the few offputting aspects of the Surface Pro 4 is its price. UK RRPs have yet to be confirmed, but the Surface Pro 4 will start at $899 + tax for the 128GB, 4GB RAM, Intel Core M3 model, up to an imposing $2,199 for 512GB of storage, 16GB of RAM and an Intel i7.
Of course, these are premium machines and priced accordingly, but we can definitely see some users forgoing larger storage in favour of the cheaper iPad Pro, which will cost between $799 and $1,079 + tax. Then again, the most expensive iPad Pro has as much storage and actually less RAM than the cheapest Surface Pro 4, so Microsoft arguably offers the better deal.
The Surface Pro 4 isn't a huge leap from the Surface Pro 3, but it's clear that Microsoft has made improvements where it counts; portability, processing power and display quality have all been upped, while maintaining the best enterprise-friendly features like a full-size USB port and a PC-quality OS.
It's pricey enough to perhaps count it out as a mass rollout device, but Microsoft might not mind so much. The firm is likely to be too busy setting its sights on Apple which, on the apparent strengths of the Surface Pro 4, should be very worried indeed.
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