Christopher,
I think it depends on what you do. I can't really think of any advantage of a tail vise over a wagon visel
Main difference is building/installation is much easier. You still have vertical clamping ability, just not as wide.
Of course, an endvise can accomplish the same thing.
One could opt for a double vise or moxon as a substitute for a shoulder vise.
I don't use the vise part of the tail vise as much as I thought I would.
In the end I chose the traditional tail vise because I wanted to stay true the original bench + the challenge.