This may be more related to how we game, but we found the face cards not very useful. They don't add anything to the game, really. An exception might be the harder to describe NPCs.
The Item cards are pretty generic really, so you could use them in any campaign and supplement them with the other generic adventure cards if you wished.
The Quest cards are really cool and the main reason I bought these cards - they offer a physical reminder of what quest the party is on, with a short blurb about what its about and space on the back for notes.
To improve the cards, imo, I would have liked more item cards, fewer face cards.
As a minor note, aesthetically, the quest cards are very nicely done. I find all the other cards a little "cartoony" and not as well drawn. But everyone has their individual tastes and it may be these are just not to mine.
I liked this mini very much, it has some great details and the pose is suitably heroic without being overly dramatic. My only problem was also the sword arm, it was quite difficult to attach. I ended up cutting a good bit of metal off to get the pieces to mesh and the angle of the blade was very awkward to attach (even though it looks great! what price art, eh?)