FWIIW, I and several other engineers left a large company with all the standard large company HR BS for a small company. When the small company proposed implementing performance appraisals, I lead a court revolt based on the following article:
http://www.entrepreneur.com/humanresources/employeemanagemen...
My email to my boss:
"[T]hey are a way to document poor performance-in other words, a step in the firing process."
Bingo. Henceforth I will consider a (big company style) performance appraisal the equivalent of a "pink slip" - notice of the company's intent to fire me.
On the other hand, I will welcome an open and honest discussion of my performance at any time. I would expect a more substantial discussion periodically (at least yearly), preferably with the openness and honesty aided by judicious application of beer.
P.S. "Some of us" were BSing about this this afternoon and came up with a good analogy... You wouldn't do a "yearly performance appraisal" with your son, once a year beating the tar out of him for all the bad things he did and then giving him a gumdrop for the good things.