The Buckets of Doom can be noisy on rough roads. The wire handle on the bucket is the culprit. On smooth roads it isn't problem.
If you can take off the handle, these panniers won't make any more noise than any other Arkel pannier. Make sure you line the inside/bottom with foam. That way your stuff won't be rattling around making noises.
P.S. The Buckets of Doom are getting impatient. They want out on the open road!