I have quite a few cardstock buildings on the layout. They are particularly useful as backdrop flats.
I find them pleasing and relaxing to build.
The challenge with these buildings is blending them with other structures. There is no way to age them or change their color tone. Depending on your style in aging buildings, they can look a little like a photograph dropped in among your buildings.
In general, if you tend towards a hazy look to your coloration, misting with white paint or using soft chalks (like many of the best modelers) I find the printed buildings work better. I'm usually not that good, so I have to place the cardstock buildings carefully.
Here are some examples...