No complaints about mine. There is a learning curve, but with a little experience they give reliable readings. As was suggested before, an aftermarket sighting device is an improvement over the crude notch for aligning the unit. I saw a user once who hot glued a short section of a plastic straw on his, and it seemed to work well. I would recommend the external battery pack, also installing and using the app on a smart phone as it is more intuitive than manipulating the buttons on the unit.
When shooting at a public or supervised range, there is never a need to adjust sky screens in front of a shooting position, nor is lighting a problem when shooting from under cover.
Customer service gets a big thumbs up too.
