Cincinnati Arrcos are fantastic cards. I highly recommend that anyone try them out.
The first Erlanger reprints (Red/Blue/Black/Green) are not very good. Poor stock and finish, and they feel nothing like original Arrcos, even though the box still says that they're plastic coated. (They're not.)
You can tell them apart either by the seal, or the copyright info on the box. The plastic-coated Cincinnati decks will have a Blue seal, the newer reprints have a black seal.
Then of course, you also have the new White Arrcos (no seal) that I released which do not have the exact same handling as the old plastic-coated Arrcos, but are very good when it comes to handling and durability.