Windows Phone 8.1: The good
The bevy of new capabilities that brings Windows Phone into the same league as the iPhone and Android is a big reason to like Windows Phone 8.1. But some capabilities deserve accolades for more than merely existing.
I have to admit: When I saw that Microsoft was doing its own version of Siri, I was skeptical. But Cortana actually works quite well. It understands my less-than-precise prose well, which many voice systems don't, and it usually returns relevant results or actions. In my spot testing, it was as good as Siri and a bit better than Google Now, which more than the others tends to view queries as simple Web searches.
Microsoft has made Windows Phone 8.1 work better with Apple products. The syncing with iTunes via the previously introduced Windows Phone app for OS X is straightforward to use, but what's really cool in Windows Phone 8.1 is the support for iCloud accounts for email, calendars, and contacts. (Sorry, not for notes, documents, or tasks, nor for syncing Safari passwords and websites.) That means you can use a Windows Phone with an iPad or a Mac and stay in sync. Android has no equivalent, though third-party apps such as SmoothSync fill in some of that gap. With Windows Phone, you add an iCloud account just as you would a Google, IMAP, Lotus Notes, or Exchange account -- it's an equal citizen.
The enhanced Calendar app is a pleasure to use. If you give it permission to access your location, your calendar items show an icon for the expected weather. And, via Cortana, Calendar now can give you a head's up on travel time (similar to what Apple introduced in iOS 7 and OS X Mavericks). But what I really like is that in the week and month views, tapping a day expands that day's agenda while keeping the rest of the calendar visible, so you have context. And when you invite people to meetings, you can distinguish between those who must attend and those for whom attendance is optional; if a person uses Microsoft Outlook, she'll know which category you've assigned her to.
Windows Phone 8.1: The bad
I've liked the simple, clean user interface of Windows Phone from its very first version. But I've found the OS overall too limiting, and even that nice UI doesn't scale well when you have lots of stuff to deal with. In that case, the Windows Phone UI ends up making you scroll endlessly. Unfortunately, that's still true in Windows Phone 8.1. Microsoft really hasn't figured out how to make it convenient to navigate lots of stuff.
Take the example of music; Xbox Music encapsulates many of the navigability and usability flaws in Windows Phone 8.1. After you open the app, you have to navigate to the Songs, Albums, or Artists or other kind of view of your music. There's lots of swiping and no quick-access navigation, such as buttons to switch among the different views, as iOS and Android offer. Then, to move within your music, you have to swipe, swipe, and swipe some more. There's no way to jump to, say, songs beginning with S.
You can't shuffle music either when working in a list. You have to play a song or an album, then tap Back to get to Xbox Music's Now Playing pane, where a tiny Shuffle icon appears next to the album art. And say you want to pause music. You won't see the controls for that in the Action Center where you'd expect t hem to be. Instead, you need to open a separate control drawer by pressing the Volume rocker. (If the screen has turned off, push the Power button first.)
As another example of Windows Phone treating usability foolishly, consider the start screen's live tiles. They can show badges or previews of new content, so you know to go to those apps. But they may not open where you expect. Take the Twitter app: If it shows a badge indicating a new tweet and you tap that tile, you'd expect to be taken to the timeline view in Twitter. But you're taken instead to whatever view you were in last, so you won't necessarily see what's new. But if you tap the tweet preview that shows up in the Action Center, you're taken to that timeline view, where the new tweet is. It's these little things that Apple especially has focused on for years, and for which Microsoft suffers in comparison.
The Calendar app that I like also shows such usability naïveté. When you add an item to your calendar, you can't choose which calendar to add it to from the default view. You have to tap More to reveal options like choosing the calendar. If you use multiple calendars, that's the last thing you want buried.
Although I like Cortana's voice services, I'm not a fan of its recommendations component, which seems to be a not-so-subtle attempt to throw advertising my way in the guise of personalized content -- the same disingenuous approach that Google takes in Android 4.4's "KitKat" version of Google Now. Worse, the recommendations are organized alphabetically by type, so you can't even arrange them in an order that matters to you.
By default, each email account you set up gets its own instance, so the emails are kept separate in their own mail apps. But their calendars all display in the same Calendar app; likewise, contacts also are combined. Why email is treated one way and calendars and contacts another is just mystifying. You can link email accounts to get all your email in one place, though the navigation from one account to the next, such as to access folders, is unintuitive. Another email oddity: The ability to Cc or Bcc people is disabled by default.
None of these is a horrible issue, but they all point out a continued lack of sophistication among Microsoft's UI and app designers.
Another ongoing lack in Windows Phone 8.1 is that of solid apps. Developers have understandably focused on iOS, because that's where the money is. Android apps suffer by comparison, though there's now a decent selection of OK apps there for at least broad purposes. When you get to Windows Phone, the app selection makes Android's look great -- the Windows Store has lots of basically demo and quick-and-dirty Web-based apps, but not much else.
The bottom line is that if you need or want apps, you won't be happy with Windows Phone. If you need only basic smartphone functionality -- email, a calendar, a browser, social networking, and basic utilities like maps, PDF viewing, e-books, and photo enhancement -- Windows Phone will probably do the trick. Just keep in mind that some popular apps, such as Dropbox, aren't available for it.