Pastel paper doesn't always stand up too well to hard pastels. Only a few layers is enough to polish the surface of the paper. So I really didn't expect too much.
To my surprise the Strathmore stood up quite well. It took a few layers and there didn't seem to be a problem with the paper showing through; I didn't fix it between layers either.
The pastels that I used were Derwent pastels and Lyra Polycolor pastels. The Derwents were quite nice but the Lyras were very gritty. Even so they seemed to give reasonable results.
This paper is a good alternative, especially for beginners, to the sanded surfaces which are quite expensive. It should work reasonably well with the less expensive pastel brands too.