I lost 1 in every 20 odd hooks as the pins snapped off at the first hammer blow :(
I lost another 3 or 4 because the hook is so close to the hammer area that I hammered the hook and it snapped off
I can't hang most of my pictures without crafty use of paperclips. I have cheap and cheerful Ikea frames - the backs have a loop but it can not hang on these hooks. I got round it but now my pictures hang wonky - I can live with it but annoys friends!! Again, got round that by hanging frames shoulder to shoulder and wedged door frame to door frame (over 100 pictures on my landing!!)
Not great, but kind of did the job. I will be seeking a different make in future, but not sure they will be any better. Could always move to a house where traditional picture pins can be hammered into the walls rather than drilling...!!