I don't know about unusable but it's certainly very annoying. If I could afford another phone (iPhone or Android) I'd already have one. I'm not into loading leaks or spending hours constantly re engineering my phone's OS. I just want it to do what's on the tin. It clearly doesn't. Contacts is a basic function. Email and texting are basic functions. Spell check is a basic function. It can't copy a URL from a web page but it can Cut or Share. My X10 fails each one of these tasks. They are buggy.
My Z10 certainly has some attractive features like the camera, but on the whole, I dislike it more and more and the fact that updates or fixes come at a snails pace (no matter whoever's to blame) is really annoying. I happen to be a US T-Mobile customer.
Here are just a couple of the common annoyances I experience.
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