Holy $#!^ don't do it! I had some issues with the WP8 upgrade that upset me enough to try out the competition. I left the Lumia 920 for the HTC One 4 months ago. I will say that having apps for everything and the ability to flash Rom's is cool, but that's about it. The OS sucks. I have jotted down some of my personal grievances in case anyone who thinks like me is thinking of switching. This will hopefully prevent a ton of wasted time and money.
•Overall OS is buggy and a total resource hog. It requires premium hardware specs to deliver an experience close to the smoothness and fluidity found in Windows Phone and iOS, but still doesn’t achieve that. And don’t even think about matching performance of budget Android phones vs. budget Windows Phones, not even in the same league.
•It requires almost daily reboot’s to keep performance from suffering or the OS from completely crashing. This usually depends on how many apps I use on any given day but is still far, far lower in performance reliability than Windows Phone.
•It is the most virus prone mobile OS available. This is pretty huge. In addition, Google data mines every account you set up on the phone. As soon as I set up my company IMAP account, and I mean, next day, I started receiving junk for the first time in 4 years. Absolutely unforgivable.
•Touch responsiveness is a joke. The delay on the keyboard response, for example, when you’re used to iOS or WP is unbearable for me and feels super low quality
•The graphics and icons are kind of toy which requires a launcher and icon pack to remedy. Even then, most packs I tried only covered half the apps I needed and the remaining app icons looked stupid. So I had to individually edit icons to get something acceptable to me.
•Communication apps are horrible. Mail, Contacts, Messaging and Dialer apps can all be replaced by better alternatives, but you run into issues when using one Dev’s dialer, another’s contacts app because the contacts app has a dialer that sucks and vice versa but when both are installed...... Forget it. It’s all a confusing mess that forced me back to the stock applications experience, which sucks.
•Most Android users and developers will tell you that the only way to get the best performance out of Android is to flash a custom ROM. In other words, Google has done such a rookie job on this OS that a community of non-paid hobbyists (Who are incredibly talented and people who help others to seemingly no end) are the go to guys when you want to achieve today’s standards in smartphone performance! Only, not all ROM’s are created equally and aside from the pains of flashing until you find something you like, you risk bricking your phone and voiding the warranty. Google should hire these Dev's and release something quality from the gate!
•Music library management is so painful for me. I, like many people have used iTunes for years and also used Zune and Xbox Music. Apple is the obvious winner here as iTunes works seamlessly with iOS. Windows Phone has a clean little desktop app that syncs my iTunes playlists and songs, but it’s an extra step. Android requires a desktop app and Android app combo. There are a bunch and the one I found the least annoying was TuneSync but I couldn’t get it to work via USB so it took an eternity to sync a few playlists. And, the stock music player is ****.
Honestly, I don't understand how Android has the explosive market share it's enjoying today, I hate it. When I compare it to Windows Phone or iOS, it's like a cheap knock off of what a smartphone OS is supposed to feel like. They have apps, lots of apps and some of which I will really miss. But the OS? When comparing straight up performance, integration of services, stability and reliability, polish, fluidity and built in communication suite, for me it's no contest and I can't wait to get back to Windows Phone!
Hope this helps someone!