We (Scout Troop) did a short section of the Quehanna Trail a couple years back. Off the top of my head, I don't remember which section, other than we started on the Eastern end of the trail.
I don't think it gets a lot of hikers, at least the section we did because the trail was a bit overgrown in October. Nothing that would slow you down, but the trails hadn't been walked on a lot. Only saw two other hikers the whole weekend. Plenty of places to camp along the trail.
Definitely need to bear bag - we saw bear scat in a couple places along the trail. I'm glad we cooked dinner along the trail, not where we camped, as we had one boy spill his dinner while cooking. On the way out, we stopped at a state maintenance facility to use the restroom and they had 4 bear traps for trans-locating bears.
Wish we could have shown the boys those traps before we headed out. It would have made the lessons we were teaching the boys about food handling in bear country hit home faster!