From Zac's article:
I've been using the HP Elite x3 and Windows 10 Mobile for a few weeks now, and I'm happy I went back. It's been awesome coming back to this platform and remembering why I chose it. The Start Screen is still a fresh take on what phone home screens can be, and it's super awesome being able to use the same apps on your PC directly on your phone.
I'm already using many universal Windows Platform (UWP) apps on my PC, and it's great to able to use those same apps on the go too. Outlook Mail, Microsoft To-Do, Edge, even Twitter, are the same across PC and phone. The Microsoft Store has also been updated with the new design on phones that lets you install apps on your other devices, so when I'm out I can tell the Store to install an app on my PC or vice versa.
...overall, I've been loving going back to using UWP apps on the go with Windows 10 Mobile. Using your Microsoft Account, many apps will sync your sign-in data from your PC to your phone, meaning apps like myTube and Readit won't ask you to log in again if you've already done it before. I also really like how Cortana still syncs your notifications to your PC, meaning I don't have to look at my phone every time a notification comes through.
The Insider Program is still active, and while it doesn't provide new Insider Preview builds anymore, it does give you access to Insider versions of UWP apps in the Store, assuming they still run on Windows 10 Mobile.
He comes to why it's not all roses though:
Windows 10 Mobile in 2018 is by no means a perfect experience, and I'd argue it's gotten worse since last year. Windows 10 Mobile is now in a state where no one is really maintaining it. Microsoft is only servicing Windows 10 Mobile with security updates, meaning it's rare to see any actual Windows 10 Mobile-specific bugs be fixed in the monthly patches.
I've also noticed that some of Microsoft's UWP apps now aren't always focused on ensuring that experience works well on Mobile. The most notable of which is the new Microsoft Store app, which now requires you to tap on an arrow to navigate through categories, rather than swiping through them, which is much more natural. It's also worth noting that any app that uses any real Fluent Design effects is usually pretty laggy.
A bigger issue with Windows 10 Mobile in 2018 is the lack of apps, which is only going to get worse as old Windows Phone 8 apps are pulled or stop working, and as UWP apps move on to support newer versions of Windows 10. Progressive Web Apps (PWAs) do run on Windows 10 Mobile, albeit very poorly. This is because Microsoft's implementation of PWA support on Windows 10 Mobile was never finished.
PWA also doesn't support service workers on mobile, meaning things like push notifications don't work on the platform. As such, apps like Twitter won't inform you when you receive a new tweet or message. PWAs on mobile also eat battery life like no other app I've ever seen, meaning if you're a heavy user of Twitter, Windows 10 Mobile is a rough place to be now.
Spotify is dog-awful and shouldn't be used at all. It's a slow mess that isn't even supported technically. It still works but is very buggy. On the flipside-ish, Slack is an app on Windows 10 Mobile that still works great, is fast, smooth, and functions as it should. Slack has abandoned its Windows Phone app too, but at least their app works well. Unlike Spotify.
He concludes:
However, Microsoft's abandonment of Windows 10 Mobile is very apparent in 2018. When compared with Android and iOS, Windows 10 Mobile is just so slow and is starting to miss out on new features that other platforms are introducing. While I personally enjoyed my time back on the platform, I can't say it's an overall "enjoyable" experience anymore.
...When I left Windows 10 Mobile in 2017, it was still basically on par with iOS and Android, but that's no longer the case in 2018. I'm going to be picking up the OnePlus 6T next week, with plans to make it my primary phone with all of Microsoft's Android apps onboard.
You can read the whole article here on WC. Well worth a look.
Me? I still run the Alcatel IDOL 4 Pro with my second SIM card in - and I could honestly use it to run my life - PIM, email, Office, Slack, podcasts and even games. The only showstopper for me is, as documented in many flows on AAWP, the way Twitter has restricted access to its DM API, meaning that if I get DMed then there's no notification at all in any Twitter app or PWA (etc.) under Windows 10 Mobile. Ironically, this isn't all W10M's fault (for once) and was an external factor that impacted other platforms as well. But, as Zac mentions in passing, the lack of complete PWA service worker support in Edge means that even Twitter can't produce a client with working DMs now. And that hits me hard.