They're great!!!
Installed with provided hardware, updated kit from Wald includes clamps for larger rack tubing and work without problems. I have never used the factory clips to keep them closed. From day 1 I've used a bungee cord below one side to below the other basket---no rattles.
They hold enough that I put a front basket on to counterbalance the weight and it provides a more secure feeling, especially in side winds.
That and what himespau posted.
Bookbag is for eggs and bananas.