On the good side, his trades for position players (McGwire, Renteria, Rolen, Edmonds, Walker) tended to work out much better than his trades for pitching (Mulder) -- and we're actually in pretty good shape when it comes to starting pitching.
In fact, if you set the Mulder deal to the side, he didn't really lose any of his prospect for vets deals. Yes, that one hurt, but on balance, those deals made the Cardinals the force they were -- that, Dave Duncan's magic, and Albert Pujols falling from the sky.