The tricky second album. That's probably the best way to describe the OnePlus 2. After the surprise success of the OnePlus One there were big expectations for its successor, so has the fledgling Chinese brand delivered?OnePlus has dubbed its new phone 'the 2016 Flagship Killer', a claim that's more than a little far-fetched. So how about a more grounded claim of 'the 2015 Flapship Killer'? If On..