Following the announcement that Windows Phone will be Windows 10 in the near future, does it still feel like a smartphone operating system? We got some time with a preview handset at the Microsoft announcement press conference in Seattle to see whether the death of the Windows Phone guise is a sensible move.

From Cortana, Photos, universal Outlook and Maps, to the notification pane and a reading mode in Project Spartan, Windows 10 actually gets a lot of features from Windows Phone, rather than the other way around.

The phone version isn't just a tweaked version of Windows 10 for PC though. For a start (no pun intended) it has a feature set familiar to Windows Phone 8.1 – but many elements will be improved, addressing a lot of user requests – in many ways feeling like "Windows Phone 10" (which, while not the official title, seems a natural adoption) with some of the PC elements. Windows 10 devices on PC, tablet and smartphone will also be able to "talk" to one another more easily, which is a big take-away point of the incoming update.

The phone's Start screen still has three tile sizes (it's unclear if there are more at this stage), plus folders, just like Windows Phone 8.1 but if you use an image it fills the screen and sits behind the tiles. It's not clear if tiles can still be transparent to show the background, which wasn't possible at this stage, but we expect is the result of a bug in the build we saw rather than a deliberate design decision)

The list of apps gets a useful addition: newly installed ones appear at the top of the list as well as in the right place in the alphabet, so no more endless scrolling through the apps and settings.

Cortana syncs searches and things you're tracking between your phone and PC, and the improved voice engine is better at recognition, and at knowing when you're refining a question (you can go from "tell a joke" to "tell another").

Both Settings and the Action Center are much improved by some simple changes. Settings is the same app as on a PC – which means, finally, it is searchable. The Action Center also looks like the new PC notification pane, which means you can dismiss one notification from an app without clearing them all, and while you can still only pick from a limited list of settings you can expand the list of controls that you've pinned to the top to show two or even three rows of buttons.

For phablets like the Lumia 1520, being able to pull the virtual keyboard from the top of the screen to sit at the side so it's easier to reach all keys with one thumb when you use shape writing looks very useful – or you can dictate into the keyboard (in any app that loads the full keyboard). We didn't get to try that out, but it worked well in demos.

These are all improvements to current Windows Phone features. The Messaging app is also improved – because it gets integrated messaging back – meaning you can send text and Skype chat messages to the same person as part of the same conversation, just as you used to be able to swap between text and Facebook messaging. Skype will need to get better as delivering messages reliably is an essential for this to be useful, but it's nice to see the option return, and it will also work with the SMS alternatives that carriers have planned. We've seen two different styles for this – one looking like Skype and the other like the familiar Windows Phone Messaging app.

The phone dialler seems to adopt a new look; it looks like the new Settings, and Voicemail is one of the tabs at the top instead of just a button to call your service (that only works if your operator does visual voicemail of course).

We also love the new message notification, which has a box where you can type your reply straight away, instead of having to tap-and-wait for the app to load before you can answer – or you can flip to a phone or Skype call.

Another feature making a welcome return is the endless scrolling agenda in the calendar app – but that's now the same Outlook app you'll get on your PC, with a view sized to work on the smaller screen, and the same way to switch from day to month view just by zooming. It has some Outlook features too, such as colour-coding appointments with categories.

Addressing critics who have pointed out that the Apple iOS Office apps have more features, Microsoft Word now gets the flow view that makes it easier to read documents – and Outlook uses Word for all emails, so you get all the formatting controls, including table styles plus document tracking features, from within that. Swiping to delete or tag messages works very nicely on the phone screen too.

Finally the plethora of Windows Phone cameras goes away; Smart Camera is gone, as is the difference between the Lumia and Microsoft cameras which caused some issues with then-Nokia phones.

Windows 10 gets the Denim camera – on PCs and all phones – with its fast shot mode, which works well. You can press-and-hold the camera shutter button – whether physical or on screen – to start shooting video much more quickly, you can extract photos from videos and make living images for them, or create action shots after the fact. You can even blend multiple exposures into one HDR (high dynamic range) with the magic wand tool.

There's now only one photo viewer too; the recent pictures button on the camera screen opens the (updated) Photos app, just showing recent images. This will do the same auto enhancement of images as on the PC.

Similarly, instead of five different mapping and navigation apps – some of which Nokia might or might not update, as the company still owns and runs Here maps and its data – you'll get one Maps app that does everything from searching for places to showing directions (picking walking or driving automatically by distance and letting you choose transit as well) with a route that takes traffic into account, 3D views and a list of favourite places. And you can drive the interface with voice using Cortana, which will be safer in the car – and means the places you look up on your PC with Cortana will already be in your list of recent searches on your phone.

These are all sensible and welcome improvements, but that's not all. Microsoft has done another sensible thing: Windows 10 is all but the same on small tablets as on phones, though the tablet version will have the desktop, because on an Atom tablet you can run desktop apps – which makes most sense when you dock it to a screen and monitor.

But when you're touching it, a small Windows 10 tablet will work almost exactly like a phone with no SIM in. That finally makes sense of a strange dichotomy, where a 6-inch screen had a different interface and set of features and app store from a 7-inch screen – and the smaller screen had by far the better keyboard and app store.

It's also not as much of a jump to put Windows 10 on a phone as you might be thinking; Microsoft has experience putting the Windows codebase onto ARM devices with Windows RT and Windows Phone 8 and 8.1. The previous phone versions didn't have nearly as much of the Windows code as this time around (Internet Explorer in particular was very different) but Microsoft has already done the hard part – making something that needs to be as real time as a phone run with the Windows NT kernel.

Critically, more and more of the core phone apps are now apps that Microsoft can update without waiting for a full OS upgrade to make it through the carriers. That matters a lot because, as always, what's less clear is how quickly carriers will roll out upgrades – and how well Windows 10 phones will sell. So expect Windows 10 for phones to arrive "later in 2015" - what exactly that means isn't entirely clear just yet.

Windows 10 on phone looks set to clear up annoyances like the previously limited Action Center, the strange regression in the Calendar app, the sprawling Settings options and the integrated messaging that was lost in Windows Phone 8.1. Fixing all of those will make it worth upgrading – and being able to undock the shape writing keyboard or dictate into any app will be handy too.

There are lots of nice little touches, and if Project Spartan turns out to be the phone browser – which we expect but haven't had confirmed – that will be a step forward too. We didn't see any features from Windows Phone go missing, so Windows 10 – so far – looks better than the Windows Phone 8.1 changes, without losing the core experience that phones users are familiar with.

Ticking off so many things that users have asked for is a nice start – and Microsoft may well announce more features for Windows 10 phone later. Better integration and sync between desktop and phone features is a necessary catch-up to some of the Apple iOS 8 and Mac OS integration.