I have many vice/work support systems in my shop. They all have their drawbacks. I own 2 versa vice's, one is mounted on a pedestal with Delron jaw inserts, one, that I modified with a pivoting back jaw which is sitting in the corner. I have 1 patternmakers vice mounted on an independent walk around work station and a set of pana vice's on a walk around work station. With all those vice combinations my favorite, easiest to adjust and use is a Wilton 301 power arm with an old Colombian 4" vice that has been heavily modified with a pivoting rear jaw.
I used the versa vice with the pivoting jaw for many years but never felt it held the work solid enough and was cumbersome to adjust with work in the vice. After acquiring the Wilton Power arm, all the other vices are turning into dust collectors or vices when I have a friend or student over.
Dave