Thanks for the comments. I hate to admit I have to agree with the judgment on Middlebrook, and can't let myself get caught up in sentimentality.
I'm surprised the vote on Koerner wasn't unanimous though; hitting 60 and 57 HR in an era based on mid-'70s league totals isn't anything to sneeze at, and even given that he never had any shot at any career milestones, he *still* rates on the high end of the "grey" region of the HOF monitor. I think a good comparable for him in the "real" HOF is George Wright, whose best years were already behind him by the time the NA was organized; except Wright truly was average in the organized leagues, whereas Koerner was truly the best hitter for a period of about 4 seasons.
Of course, opinions differ.