Best thing about this set is the designs. Mushrooms, squirrels, owls, birds, leaves and acorns - lovely! The front of the paper is the design and the back is either lined or blank with a border (I've added a couple of pictures). I think they could have made the lined backs look better, as they do look a bit cheap compared to the border backs.
I haven't had the same problem with crinkles and smudges as the other reviewer, but I agree about the quality. The paper does feel and look like it's been made with recycled paper, so it is a bit flimsy and thin. I also own the Cath Kidston Birds Stationery Box and difference in paper quality is noticeable.
If you love the designs, I still think it's worth getting but just be aware that the paper quality might not be what you're expecting.
UPDATE EDIT 17/10/15: I originally gave this 3 stars, but have ended up using all of it and would potentially buy it again - the designs really are great, just the paper quality means it loses a star.
The design is very nice, but it's been cheaply produced. The whole thing comes over as a cheap children's set, which was not what I was hoping for at all. Some of the envelopes had smudges on, and both the paper and envelopes were crinkled in places as cheap paper does when stored. For this price I could have bought quality laid paper in larger quantities, but thought this would be fun and funky. It's ok, but a bit more 'penpal' than I had expected.