From the last line in the Mikohn webpage that Pete Sanders cites:

Player Tracking - Game Tracking (GT): "GT also deters dealer mistakes and the most common cheating techniques as well as identifying card counters."

While the system does help monitor a player's true handle, for purposes of more accurate comping, I think the real motivation to use the system, from a casino's point of view is to monitior skill level (i.e. card counting ability).

When players "voted with their feet", I think it killed the experiment. Plus the continuous shufflers can take most of the advantage out of card counting, with less complexity, if a casino chooses to go that route.