I agree with both. They are rather secure and I would have been happy to use them and leave my valuables there......if I could have figured out how! Looks like I missed the bit about putting coins in! LOL.
Don't worry - I only figured out that a coin was required because I found a locker where someone had left the coin behind! It still took a couple of goes to figure out that you have to open the door, put your bag in, insert the coin in the top slot (while the door is still open), close the door (which causes the coin to be eaten) and then turn and remove the key!