Here are a few examples:
He is a bad novelist and a fool. The combination usually makes for great popularity in the U.S. - Gore Vidal on Alexander Solzhenitsyn
...he goes on like the worker's son, like a modern-day D.H. Lawrence, but he's just another boring little middle-class boy hustling his way to the top if he can do it. - Gore Vidal on John Updike
...he seems to suffer from American cleverness: the fear of being thought stupid, or dull, or behind the times. I think that's a very bad attitude for the novelist to adopt...he's heading for disaster. - a little payback on Gore Vidal from Kingsley Amis
The reason Hemingway is easy to read is that he repeats himself all the time, using "and" for padding. Tom Wolfe on Ernest Hemingway
My favorite is a comment that Hemingway made in a letter to Charles Scribner about the writing of James Jones. But I hesitate to quote the obscenity-laced comment here (also, its repulsive images). Look that one up on the internet sometime...or email me and I'll get it back to you.