Sony has introduced the Xperia Z3+, an ‘premium’ version of its existing Xperia X3 handset. Like its predecessor, the Z3+ is waterproof and dust-resistant (IP 65/68) but features a few small hardware tweaks. For example, both front and rear-facing cameras now use Sony’s Exmor sensor and the selfie camera has been upgraded from 2-megapixels to 5-megapixels.