There are a few stores where I use a card. I'm finding that my wonging freedom is reduced significantly when I'm using it. The result, I believe, is a significant reduction in EV. Not so sure it's worth it.
Just played 16.5 hrs. and it resulted in a 204 unit win. My wonging was quite extreme without the use of a card. Sometimes I wouldn't even sit just in case the 6D pack went at all south bound. Sometimes playing only two hands then, "see ya". Lot of acting though. Maybe one day I'll have enough credit to win the AP's academy award. :-) It's amazing how much we have to actually do to beat the game consistantly. There is so much more than just betting and making play decisions.
I think player cards are great for 1D and 2D. Multi-D requires too much wonging and therefore the use of the card makes it just way too difficult to have the freedom that is needed.
Just my personal observation after years of 6D play.

