Anyone who reads this blog knows I have no use for tail vises but bottom line, who cares other than MsOK and Sam the Wonder Dog. Well maybe Sweet Maggie Dog does as long as I have a ball in hand.
CS posted a video on his blog today addressing work holding on a bench with no vises, I expect most have seen it but if not here is a link.
One of the go to books for new bench builders today is CS's. I like the work he has done popularizing hand tools and for that matter bringing old bench forms back to life. But......there's that damn "but" again, you can see the effect of his bench building books on many of the woodwork forums. It seems every bench being built has a leg vise and usually a wagon vise, those without a wagon vise have some other form of tail vise installed. Looking over some of the builds I have a hard time imagining what kind of work the bench is being built for. BTW, I'm guessing most readers skipped over his advise to look at your bench build plans and if parts of it do not look or function like the classic benches it might be wise to rethink those parts.
Most of what I'm trying to say is: Many times there are as good or better ways to hold work for whatever operation you wish to perform than a vise. Sometimes not, I use the heck out of my face vise and I wouldn't really want to lose it but for most operations, other than end work, working with out using a vise is faster and often will give better results.
I learned something from watching: I now have a name for the notched batten I use to hold work on the bench for cross grain planing. It's a good video, watch it if you have not watched before.