We spent 2 nights at Pioneer campsite #2. Since it was just myself and my husband we had the option of primitive camping or pioneer site 1 or 2.
In my opinion site 2 was the best of our options. It was 20 degrees one night and car vs primitive camping was so much better for the gear we have. Site 2 is the last site on the little side road that contains sites 1&2 and is on a plateau surrounded by forest.
The visitor center and the park at large is well maintained with extremely friendly staff. Visiting in the winter gave us the opportunity to enjoy hiking and exploring without concern for a lot of crowds.
My advice for the pioneer sites is to be aware that there's absolutely no water. I'm used to some sort of water for dishes and this is really closer to primitive camping. Second, the drop toilet smells extremely bad. I've used plenty of these and this one is in my top 2 of worst smelling! Thank God it was just me and my husband because I couldn't close the door! Aside from this it was a wonderful trip and well worth the visit.