I agree with madagas.  I think a lineup of Weiland or Bach, Slash, Izzy, Duff, and Matt could have kicked some ass.  I'm not a fan of Bach's songwriting, but Izzy would have been there.  I saw Dave as a bigger part of the problem than Scott or Matt.  His tone sucks, I don't know what he brings to the table songwriting wise (though Get Out the Door was his I think).  I think they could have made any singer work with Izzy because the song structures and guitar interaction would have been so much better. 

They needed to be a guitar dominated band and while most of CB was, Libertad wasn't at all.  Certainly there were other factors, but I see that as a big reason Libertad isn't as popular with people.  I think Libertad actually has some very good guitar parts on it, but most of the time you can't hear it unless you're listening specifically for it.