CSMs disadvantage everyone (including the Casino)
When playing on the CSM, the cards get shuffled after every round.
You are playing with an infinite deck. (Not the 4 decks that are in the CSM.)
Simple example: 5 rounds are played head on with the dealer, 4 deck CSM. It is possible that the "Jack Of Clubs" (or any identical card) has come out in every round.
The odds of obtaining a blackjack is higher in a infinite deck.
Other CSM disadvatages (for both Player and Casino):
1) No Cut Card. (This prevents a player from setting up the game)
2) Less Boxes are played (Some players will only want one or two boxes open and prevent other players from opening up boxes. Since there is no break or cut card, the table can have the same players all day discouraging opening new boxes.
3) Cards are hidden
If the dealer gets "21 out of no-where" say 3 times in a row, then the player will question any "house fixing".
A traditional shoe, the Casino has got nothing to hide and "put the blame back on the player for cutting the cards