I had the original LG Optimus G and now an G3. The G3 has a flexible plastic removable back that you can remove, not sure if that is the standard with a Dual SIM version. Some of the Samsung has a rubbery or plastic back too. My old Optimus G had a harder plastic back with a marble finish.
If one bought a $1,000 Android, on the physical side they don't seem that polished as the iPhones?
Whilst even my Optimus G (1) had 98% of the technical features as the standard iPhone 6 - as did the Nexus 4 but without proper 4G.
I am not in the customization, but I have known some people who also work in IT who simply just use them as what they are.