For my "nice" set I have 0"-6" Mitutoyo with carbide faces and a tenths vernier. I really like them. I bought them used at an auction, and checked them on micrometer standards and gage blocks to verify them.
For general shop use, I have some older Starrett and Brown and Sharpe that I also bought used. They are carbide faced as well, but are only graduated to .001". Which is fine for 99% of my work.
For students in a shop, I wouldn't spend much. Fowler or Shars is probably just dandy. They WILL get dropped, misused and generally abused. Plan to buy a new set every year or so. When I was in college machine shop, I brought my own mics and calipers because the school sets were not treated very well.
Micrometers are a fairly simple device. They need to be made accurately, but you can make one without too much advanced manufacturing. Like any quality brand of tool versus a cheap one, the differences are subtle and sometimes hard to see at first. Satin chrome barrels, quality of lapping on the faces, the finishes on the frame, the smoothness of the ratchet mechanism and the barrel lock, stuff like that. Plus the quality of the materials, heat treat and so on affect the longevity and durability. Plus the value of the brand. So while a Shars may be plenty accurate for general measuring for a while, it may not hold up as long or be as nice overall as a B&S, Starrett or Mitutoyo. You're paying a premium for the top end of a product.
