Think of it this way
Since all the 10's are removed, you are in effect starting with a true count of -4.
According to Stanford Wong, the house edge on a Spanish 21 game with S17 is .43%.
Since most PC's consider it a sucker game, you can usually get away with a big spread.
Like just about any game, penetration is vital. If you can find good pen, the game is playable.
Of course, you would have to know basic strategy and indices for Spanish 21. Since the game is only offered at a handful of casinos, it is questionable if it is really worth the effort involved.