I dislike those units personally. Optex makes decent PE beams, but those units pictured don't work in my area of the country, not to mention having a wart stuck outside on a residential building. Just not an ideal solution for the majority of the installs around these parts.
There was an integrator in-state that loved those things....hundreds of them over the same amount of installs. Nothing but a false alarm headache, but the up-side is we got a lot of work out of it.