Indeed, Paul.
I also have a few rifles fitted with synthetic V-Mach items - still all going strong.
As indeed are the ones that I have fitted with the TbT and Welsh Willy items (as Pete says above) which have also been fine.
Seeing Nick's information on failure rate sheds good light on this.
And I suspect that a good proportion of those that did fail may have been down to other factors - insufficient preload being one of them, where the spring could pull the end of the guide away from the end block and then slam it back into the block.