I have a bunch of vises, and no high end Kurt or Glacern. They are mostly ok. I've found that sometimes a screwless vise is the answer. Other times a lock down vise is the only way to go. My little high speed machines have screwless vises (some guys might call them grinder vises), and I have been ridiculed for using them on my high speed mills, but with modified jaws they allow me to use the work envelope of the machine without slamming into the cabinet doors and knocking out the windows. A mill vise with half the range would still bang into the doors. I've got little 1 inch insert vises, and 8 inch mill vises and a whole lot of stuff in between. It all gets used. There are two 6inch mill vises on the table of my big mill, only because the 8 inch vises would require me to cut holes in the table enclosure to turn the screws, but they were both in use similarly on a mill I retired a couple years ago, and will be in use on a similar machine again in the future.
I get the buy once advise, but if I bought a Kurt I wouldn't have everything I need to do the jobs I need to do.
I'd have to go out and count them, but I've easily got well over 20 precision or semi precision vises. If I counted cheap drill press vises and bench vises the count would probably jump to over 30. I use them all. Not everyday, but I use them.
A while back I visited a successful machine shop that was closing down due to owner health issues. I bought all of his mill vises, and a couple angle vises. Own protractor style and one sine vise. Not a single vise in his shop was a Kurt or a Glacern. He had been doing business in that location for 40 years. He was still busy, and the lady who was his shop manager was still there cranking out parts to finish orders as he was closing down.
That being said, if you have the money to spend you can't go wrong with a Kurt Vise. Its just going to eat up a lot of your budget.