I think its up to trial users if they want to post their reviews on their blogs or any social media.
Anyways this is my first impression of the build of the LG G4. Do note that I got the metallic grey plastic back. However I was able to get a feel of the phone with the leather back for a few minutes at the event. To me, I prefer the leather back. I find the phone to be lighter with the leather back then the plastic ones. Leather feels really good and enhances the phone's grip.
Okie so back to my leather back review set, I find that the phone really has a good build. Even though its abit thicker than LG G3 or infact most of the flagship phones, it's actually nice to hold in your hand due to the subtle curve of the phone

The grey back cover actually has this feeling of a fake metal, which have been growing on me this few days haha. The bad thing about the plastic cover, is that it can get quite slippery if you have sweaty palms.
conclusion on the build is that it is really a nice phone to hold and even though it is a plastic build and not metal, it does look and feel premium. You guys have to see and feel it first
check this website out to see the close up angles of the phone,
http://www.slashgear.com/lg-g4-hands-on-leather-and-a-smarter-camera-28381076/