Is any of the following blackjack instructional DVDs worthwhile:

1. Blackjack Science Counting and Betting Techniques with Semyon Dukach - Dukach was with the MIT Blackjack Team.
2. Blackjack Science Advanced Techniques with Semyon Dukach - This second DVD has been reduced in price from over $200 to about $25.
3. 60 Minutes to Winning Blackjack DVD - with members of the MIT Blackjack Team.
4. Beating Blackjack with Andy Bloch - Bloch was with the MIT Blackjack Team.

Does anyone recommend any other blackjack instructional DVDs?