I own/have owned several Windows Phones (920, 930, 1520), and overall I really, really like the OS and hardware. The problem is as mentioned a lack of apps and reduced/missing features in apps compared to other platforms. You'll also miss out on several features (such as Cortana) if you're living in the "wrong" country. Due to this I'm currently using a combo of the iPhone 6+ and the HTC One m8 (flashed to a Google Edition, now on Android 5.0) as my daily drivers, but the instant WP starts getting treated as a first-class citizen I'm switching back.
iOS has the apps, but the OS itself doesn't really do it for me. Android has almost the same selection of apps (and some that isn't on iOS), and you can customize pretty much everything. I like that, but the OS doesn't feel as "smooth" as WP, and the camera no matter what Android phone I've used leaves something to be desired.
Edit: I should probably add that despite the lack of apps, WP has some gems in the store. Tweetium is probably my favorite Twitter client on any mobile platform, Nextgen Reader is a great rss reader, Poki is a lovely Pocket client, Readit is a beautiful reddit client, Nokia's Here suite of apps are amazing (offline navigation and maps, for "free"!) and the same can mostly be said for many of Microsoft's previously Bing-prefixed apps, and the Lumia camera app is a joy to use when you want to do more advanced shots.