Reporting back. We did both the trail from York down to Monkton MD. The Pennsylvania section did have small gravel,but not much, we had no problem on the trail at all. The Maryland part was hard packed dirt, no gravel at all, we made much better time. All in all an excellent trail. I'm not sure how it would be if it had rained a lot, we were lucky, the weather was beautiful and the trails were totally dry.

Also on PA side, good stops, though the New Freedom cafe was packed and it seemed all the other restaurants in the town were closed.

Excellent ride on both the road bike with 700x23 and the very loaded touring bike with 700x32 tires.

Thanks everyone for the tips.