I just got mine...
The cards are of good quality. About the same stock as Bicycles, with a
smooth finish. They're not your standard "poker" size though. They are narrower by 1/4 inch and
longer by 1/32 of an inch. This would only be of concern if you were planning on the cards together
with other "regular" sized cards. (I marked down one star because I personally would have preferred
if they were poker sized).
Also, the cards come sealed in a plastic bag, not in box. An
easy solution is to put them in one of those card-sized envelopes. In fact, it would be a good idea
to get several of these types of envelopes since many good ESP effects use them anyway.
Other than that, I've not gotten through the book yet (I mainly got this because of the cards).
But it's already evident to me how just about anyone can perform some pretty mysterious effects with
this package.