I've had the deck for about 8-9 months, which isn't long, but the deck was only released in 2002, so many folks won't be able to answer for durability beyond a few years time.
The card stock is thinner than regular Tarot cards, perhaps it's lacking a plastic coating or something, I don't know. I don't riffle-shuffle much with these (but occassionally do) because they are so thin - they warp easily if someone uses them with a heavy hand. This thin stock may be due to Monolith Graphics limited choices in card stock, when offering these for publication... both of their decks are this way (the Madame Endora and the Gothic Tarot) and both are exactly 3x5", which is not a standard size for cards either, but still works. So my guess is it was a cardstock cost and supply kinda thing.
Easy to shuffle? I have large hands for a woman, long fingers, so they're not too hard for me. They are overszied, and meant for large hands, man's hands, if that makes sense, in how they fit the palm.
It scratches, my cards already have scratches, yes. I use this deck for daily draws a few tiumes a week, and for readings, say... a few times a month. I keep the cards in a purple bag between uses to keep them protected, and handy. They've held up ok so far, but I do treat them a bit more gently since they're so thin.