I got my decks today, so first impressions...
The stock used is VERY FIRM, stiffer than ordinary 1800s. Bee stock? Clearly they were made to last.
The marks are plainly readable, no code or system to it, much like the marked Phoenix decks or the Ultimate Marked Deck - but you need GREAT eyesight at times to distinguish the markings. They are actually concealed in the "cracks" of the design, and if there's extra cracks nearby, well - you need to look carefully. But I can confidently say this - it would be nearly impossible to figure out it's marked using the "going to the movies" riffle test. There's so many little cracks and age spots in the design that EVERYTHING is moving! You'd have no idea where to look, precisely, and the markings are quite small as well as being camouflaged by the faux aging.
In summary, my first impressions are that it's a very good deck at a great price, but you need to practice reading the markings before you attempt using it in a trick (or a crooked card game). I love that the marked version goes for the same price as the unmarked ones!
FYI: how to tell the difference between marked and unmarked: marked decks use a standard black USPC seal, while the standard decks use an aged-look USPC seal in the opposing color - red on the blue deck, blue on the red deck. If you don't like the look of the standard sticker seal on the aged deck, just remove it completely.