The difference between them is that Kiper actually has legitimate sources and contacts around the league who clue him in to rising players, sleepers, etc. He works year around researching and gathering information on every player for that year's draft.
McShay is a leach who steals info from everyone in the business and projects it as his own. He has no integrity and no talent.
I actually respect Kiper because of the work he puts in. McShay is a parasite who doesn't have the first clue how to evaluate talent on his own.