I own two of Veritas's screw-action holddowns.
I have used them for several years, and found them convenient. A couple of weeks ago, however, one of them broke right at the pivot point. Looking at the poor, broken thing, it seems a miracle it held up as long as it did. Not much meat at a critical location.
I never tightened it other than by hand, nor did I strike it with tools. The point I am making is that they were not abused.
The lady at Veritas offered to sell a replacement arm to me for $21.50, but by the time I pay the shipping cost to Japan, I could almost buy a new one.
Chris Vandiver kindly gave me a couple of his Peter Ross's handforged traditional holddowns to use, and they are absolutely wonderful! I highly recommend them.
Simple is best. Caveat Emptor.