The side buttons are relatively sensitive compared to the 920, but I'm getting used to certainly still there. Have now but a few times accidentally activated the camera. Unfortunately, colored sleeves are not yet available on the market.
The 5 MP camera, 720p display and 1.7GHz dual core are all no deal breaker, but rather contribute to an extremely long battery life. The display is great for everyday use and also for movies, reading surfing, articles with small print and write mails I do still prefer on my iPad mini Retina. During a telephone conversation etc. I could not perceive any negative effects like muffled voice, however, I am not a frequent callers.
If you like Windows Phone 8, a super cell phone, for all that do not want to spend 600 for 1080p.