Have you used other sleeves before?I assume you mean other sleeves for dominion cards? I haven't, I've asked my brother if magic sleeves fit, he tried it and said they don't. I don't have any other sleeves I could use, so I ordered these right away.
I was just more curious how these sleeves compare to the Fantasy Flight
I'm going to chime in 9 months late. Fantasy Flight sleeves are thick and inflexible. They're very durable. Cataphract sleeves appear to be penny sleeves, which are much thinner. I do not (yet) have any Cataphract sleeves, but I use Mayday's penny sleeves for Dominion. They wear out relatively quickly, but they're less than half the price and they take up much less space.
For all my other games that use cards, I use "premium" sleeves. For <200 cards, that's fine. For Dominion I'm sticking with penny sleeves.
At the time of this writing, Cataphract's Euro-sized sleeves are sold out. I'm hoping they restock soon, since I'm looking to leave Mayday behind. Mayday's quality control has always been awful, but they recently changed something about their manufacturing process. Now all their sleeves have a seam at the bottom that makes them almost unusable for my proxying purposes (and easily distinguishable from their older runs). I'm fed up.