As a spec sheet exercise, the new Lumia flagships, the 1.8GHz six core Snapdragon 808-powered Lumia 950, and the 2GHz eight core 810-powered Lumia 950 XL, do all the things they're meant to do. With a 5.2 or 5.7 inch AMOLED screen, respectively, a 2560×1440 resolution, 3GB RAM, 32GB storage, microSD expansion, 20MP optically stabilized rear and 5MP front cameras, and the usual array of sensors, they solidly fit in the "high-end" category.

Their most exciting features aren't simple specs, however. They're Windows features: Hello biometric logins, and Continuum.

On the Hello front, the phones both support iris recognition-based unlocking. Unfortunately, it wasn't possible to actually try this out on any of the handsets that were available to play with. This feature, when the phones ship in November, will initially be in beta, which is a little concerning, but right now we simply have no idea how well it will or won't work.

Continuum, however, was ready to try. The basic premise of Continuum is simple enough: the smartphone is a powerful pocket computer, that contains (or at least, has access to) all your data, and many of the apps that you care about. But lots of tasks—editing documents, writing long e-mails, even flipping back and forth between a handful of tabs in a browser—are awkward, at best, on a smartphone. Continuum is Microsoft's solution: hook your phone up to a big screen, a mouse, and a keyboard, and you'll be able to use those apps with the big screen, with the better input devices.

Continuum support places demands on the hardware. Specifically, it requires the smartphone's system-on-chip to support multiple displays, because it keeps the phone display running, and usable, even while it's using an external screen. The Lumia 950 and 950 XL will be the first phones for which Continuum is supported and advertised. You'll be able to hook up devices directly, using Bluetooth for input and Miracast for display, or use the new dock that Microsoft has. The dock connects to the phone using USB Type C, and offers 3 full size USB ports, a full-size HDMI port, and a full-size DisplayPort.

Either way, the experience feels like a taste of the future: running on the big display, the apps take on the same look and feel as they do when run on a PC running Windows 10. They respond to keyboard shortcuts in the normal way, they respond to the mouse in the normal way, and they act more or less like regular apps.

In some ways that's not surprising: they're Universal Windows Apps, and the entire point of Universal Windows Apps is that they work the same way on tablets, on PCs, and on phones. But understanding that theory, and seeing it working in practice, are two very different things. Continuum really does work. Is it actually going to prove important and desirable? That I'm less sure of.

The 20 MP camera seems competent, but real testing is going to have to wait for a proper review. Past Lumias have had good cameras before, but been hampered by poor shot-to-shot time, and it's not clear yet whether Microsoft has fixed that problem.

Perhaps the most disappointing part of the phones is their styling. The past Lumias have all been striking, using both color and design to create a distinctive look with a strong familial resemblance across the full range. The new ones look extraordinarily generic. Before, you knew just from seeing the phones that Nokia or Microsoft made them.

These ones? Anybody could have built them. In cursory examination they still felt solid and well built enough, but visually they're mundane. The contrast with Microsoft's other big hardware line, the carefully engineered Surface, is significant.

A new Windows phone wouldn't be a new Windows phone without carrier issues. The new phones will be available unlocked from Microsoft's store, $549 for the 950 and $649 for the 950 XL. They'll support AT&T and T-Mobile's frequencies, but don't appear to have support for the Verizon or Sprint CDMA networks. Moreover, there appears to be some kind of exclusivity with AT&T. The 950 XL is available on Microsoft's store unlocked. The 950 presently isn't. AT&T, however, has announced that they will be carrying the 950.

Update: CNET, which originally stated that the 950 was exclusive to AT&T, has now retracted that claim, saying that the deal is not exclusive after all, and that both the 950 and 950 XL will be available through the Microsoft Store unlocked. However, the 950 is still not appearing on Microsoft's online store. Only the 950 XL is showing up.

Listing image by Andrew Cunningham