I am not warning you against purchasing these CDs or subscribing to these services.  I bought Broderbund's Census Bundle of eleven CDs and Marriage Bundle of twelve CDs, and I subscribe to Ancestry.com, Genealogy.com, and GenealogyLibrary.com.  I would unhesitatingly purchase these CDs again, and I have no plans to discontinue my subscriptions to the mentioned online databases.  However...

As a novice genealogist, I naively expected that the census CDs were complete for the years covered.  Now, as an experienced genealogist, I can see how naive that expectation was.  There simply is no complete index to the US censuses, and Broderbund means it when they labeled the CDs as covering "Selected Counties."  And even as a novice genealogist, I knew enough not to expect the data to be error free.  What I did not remotely expect, even as an experienced genealogist, was fundamental and massive flaws in the databases, ones that wasted untold hours of my time and caused me enormous frustration until I uncovered them — not to mention the worst effect, that bad data produce bad genealogy for everyone using these databases.