Having owned a OnePlus X a few years back - dual glass front and back is not necessarily a great idea. The OPX was so slippery that it would slide off any surface, even horizontal ones. Your only hope was to put a case one it, which negated the aesthetic point of rear glass.
I feel the same way. I much prefer a plastic back with a nice finish. It makes the phone lighter and more durable and the texture can easily rival that of a nice soft-touch glass finish.
