The Black Acorn Backs are still one of my all time favorites.
I like the Black Acorns too. But of the thick stock (casino grade) decks we did at USPCC I think the Smith No 2 are my favorite. It's not known but the Cambric finish of the Smith No 2 was actually printed on two different stocks. We printed about 6,000 on regular casino paper and another 6,000 on an experimental paper. There is no indication whatsoever on the tuck but if you use a black light you can see the difference in the stock. One of them also weighs quite a bit more than the other. Just a trivial bit of info.
I did all that experimentation because I really wanted (needed) very firm cards and at USPCC the thicker casino stock gave the firmest deck.
Now that we are branching out and also printing at other factories we can get cards that are both very thin and very firm. This pleases me a lot.
The Zenith deck by Paul Carpenter is the most perfect alchemy we've managed so far and they are amazing handling cards!