Interesting. I didn't know preferential shuffling was illegal.

The amount of advantage for a counter varies according to the particular table rules, of course. I've noticed that tables with good rule sets are getting more and more rare these days. I'm seeing a lot of things like single deck games, but where the blackjack payout amount is 6 to 5. (Thus reducing the advantage for a counter who keeps a side count of aces in a single deck game, in addition to simpky reducing the overall player advantage.)

I'll bet it's all part of the casino backlash against the increased availability of information on blackjack strategy and counting in this internet-age.