It's a little under two years since I last bought a new mobile phone, so when my operator offered me an early upgrade and a shift from a 3G network to its 4G LTE service with four times the data allowance, I decided it was time to take advantage of the deal.

I could have gone back to iOS or Android. After all, I still have a library of iOS apps on my old iPhone 4 and on my iPad, and the same for Android on my Nexus 7. But I've been using a Windows Phone device as my daily driver since my last upgrade, and I decided I'd stick with the platform for my new device, choosing the new Lumia 930.

So why did I stay with Windows Phone?

It's not about the apps or the camera

While Apple's iPhone 5s has a 64-bit ARM SoC, there's little else to distinguish the current generation of hero devices. They all have excellent cameras, most have separate sensor processors to handle motion detection, and they all support Bluetooth Low Energy (which Apple has branded as iBeacon) connections to external devices. They've also all got HD-quality displays, with "retina" resolutions, and fast LTE radios that work anywhere in the world, as well as fast WiFi chipsets.

I wasn't driven away by the so-called app gap. With test iOS and Android devices on my desk, I'm fully aware of the state of app development and the app stores on all three platforms. Windows Phone does lag the other mobile ecosystems, and where key apps are on all three devices, the Windows Phone app often doesn't have all the features of its more mature rivals.

But the apps I want and need are there, and where there aren't official apps, there are good and effective third party solutions.

It also wasn't the camera that kept me. Nokia's camera technology is superb, especially on devices with its PureView camera modules. I find the Lumia's camera fun to use, and in conjunction with Windows Phone's Lenses apps, an intriguing test bed for computational photography. But it's not the same as a purpose-built camera, with a large sensor and interchangeable glass. So while the Lumia camera has replaced the point-and-shoot I used to carry, I still go back to my DSLR for serious photography.

They're both important reasons, one pro (camera) and one con (apps). But neither are enough to make me either leave or stay with an ecosystem.

It turns out that, for me at least, the reason to stay with Windows Phone was more about how it fits in with how I live and how I work -- in the ways I have built that most personal of devices into my life.

The real meaning of "productivity"

For me, the key to keeping me as a customer isn't gadgets, or software. It's how you help me live my life. It's no coincidence that Microsoft's new message is around productivity -- giving you the tools you need to get the stuff you want to do done.

Microsoft's Office 365 has become a key component of my day-to-day work and personal life, together with consumer services like OneDrive. I don't need to worry where my files are, or whether I've patched the office mail server. It's an approach that's convinced me of the value of cloud services (whether they're Microsoft's, Google's, Amazon's, or Apple's). I can work anywhere: At my desk in my office, in the coffee shop down the road, or under the redwoods outside a friend's house in the Santa Cruz Mountains.

Windows Phone links into that cloud of personal and work data, and acts as part of my personal workflow. I can triage mail while connected to the London Underground's WiFi network, check documents I've been sent, and even edit Excel spreadsheets. Detailed work gets handled on my other devices, but it's the phone that's the gatekeeper.

It's not just the ability to dip in and out of work that's happening elsewhere. It's also the ability to use my Lumia to start new work in the mobile version of OneNote, or to use its camera to quickly capture information that can be used elsewhere.

With OneNote notebooks in the cloud at the heart of how I work, it turns out that one of the most useful tools on Windows Phone is Office Lens, a quick way of taking photographs of slides and other presentation materials and dropping them into OneNote. Office Lens will reformat slides automatically, cropping out background and handling perspective adjustments -- as well as supporting OneNote's cloud-based optical character recognition.

Office Lens has become a key part of my workflow, as I use it to deliver images from presentations straight into an open notebook on a PC or tablet, so I can have them ready for annotations as I take notes in a meeting. A recent upgrade now lets me work with arbitrary notebooks, keeping those images away from the default OneNote notebook. It's easy to use, and the automatic image editing keeps me focused on what's being presented, and not on getting neatly formatted copies of slides into my notes.

The right tool

A phone has to be a tool, not a toy, and it has to be the right tool for you. They're personal devices, even if they're issued by an IT department. I have the advantage of being my own boss, and running my own Office 365 account, but I still set security policies and manage the devices and services I use -- after all, that device contains a lot of personal information that needs to be protected.

Having phone, tablet, and PC be all part of the same cloud sync environment is the real reason why I decided to stick with Windows Phone. It wasn't the apps I'd bought, or the games I'd played, or even the excellent photography tools. Instead what really mattered was the workflow I'd developed over the last two years.

Oh, and the Lumia 930? There's a lot to like as a device, with array microphones for voice recording and a 20Mpx camera for all those photographs. And the real winner? For someone as disorganized as me, its fluorescent orange back makes it very hard to leave lying around.