Probably doesn't help the OP, but here is my mill vise story for the sake of other readers looking to purchase.
I have two of the Tormach 4" 'CNC vises'. First one is near perfect, the second was ordered about 6 months later with the fixed jaw out of square by .005 and with significantly more drag on the screw. The bed heights are within .0005, amazingly. #2 works fine after I trued it up, but would not buy another based on that anecdote.
Really wishing I put that money toward the SMW fixture plate/modular vise combo if I had to do it over. My PM-25 column is not all that rigid, so getting down 1.5" closer to the table would really help mitigate the chatter I get when blasting through aluminum.