The general opinion seems to be that Jet mills are pretty good. Some are better than others. I've got a JVM-830 (no longer sold) that in general is quite nice. It's a pretty basic knee mill, but the "fit and finish" are quite acceptable. Not up to a Clausing or Bridgeport, but quite good enough.
Try to go see the mill you want to buy before you buy it. There is nothing like seeing machinery "in person." My Jet dealer referred me to a local machine shop that had just bought a mill like the one I was considering, so you might see if you can get a reference like that if there is no dealer nearby or if the dealer doesn't have a machine like the one you want in stock.
Try to make a living, not a killing. -- Utah Phillips
Don't believe everything you know. -- Bumper sticker
Everybody is ignorant, only on different subjects. -- Will Rogers
Law of Logical Argument - Anything is possible if you don't know what you are talking about.