Things I liked: It's sturdy and simple.
Things I would have changed: The advertised 700+ fps of my new Winchester M-14 reproduction rifle is not enough to flip the targets regularly... even from 15 feet. Nor will it release the targets by hitting the top one. You can hit it all day with nothing but a pleasant "ping". The targets appear too heavy for most air rifles.
What others should know: The concept is attractive. But you need a lot more than 700fps to have any fun.