I did a five day trip up to BSP last week (after the Labor Day rush). Three days were backpacking out in the central part of the park in the Wassataquoik Lake and Russell Pond with a trip over Katahdin from the NW basin to KSC followed by two nights at Daicey Pond. No rain and clear skies for five days. All of our staff interactions were excellent. We saw several new/replacement structures that will improve future visitors experiences. I expect the new winter cabin at Daicey is going to be in big demand.
We saw a few thru hikers but our itinerary really didnt line up with the typical spots we would see them except on the Hunt trail out to Daicey Pond late in the afternoon.
I learned a few new things and have a definite must camp shelter in the backcountry. Hard to beat!