I just mounted this in the attic of my two story house with concrete roof tiles and I'm getting 100% signal quality. I chose it because I live 30 miles from the stations, so I figured I'd get something that can do double that to account for attenuation through the roof.
When it showed up I figured it would take some assembly as the box is tiny. Took me maybe 15 minutes to get it together. The instructions are a little confusing because the first two figures show the reflectors installed upside down. Just use the photo on the box as your guide.
I mounted it in the middle of the attic as I read that signal is better the further it is from any barrier (the roof). Got it pointed in the general direction, and ran the wire down the wall, and plugged it into an HDHomeRun Connect Duo tuner. Set up the software, scanned for channels, then got the HDHomeRun signal test app on my phone and went back into the roof to fine tune the orientation (was off by a few degrees). Now I'm getting 100% on all the major networks.
If I were mounting an antenna outside I'd get one that uses less plastic, in my experience UV exposure will make plastic brittle and break over time.