This has been an interesting thread, all the more so as, when I resumed playing the DB some 23 years ago, I resolved not to monkey about but stick with Spiro Mittels. And they have served me very well in that time with no breakages. What has been less satisfactory has been the performance of the tail wires, with three breakages. On two occasions it has been just before the gig when tuning up - or in those cases down. The first time, though, I was mid gig and the whole lot let go. I was using one of those old cast aluminium three point bridges. So the people in the front row were assailed by the bridge and the three loose cups that it stood in. Fortunately I recovered all the bits.
In each case the bass was German and the tail wire was out of soft material not unlike a welding rod. Today the standard is either braided synthetic cord (Upton) or light gauge yacht rigging.