If you have read Chris Schwarz's book on Workbenches, you would know that he is very much in favour of a kind of tail vice that he calls a 'wagon vice'. I hadn't seen one of those and thought it was a neat idea.
Now here is what happens when someone starts something like that - a made-to-order wagon vice - yours for US$325 plus postage! More than most of us would spendon our entire tool kit!
I like the vice, but really, it's just a vice - who is going to spend $400 or more on a vice!