Rolled limestone dust is not gravel. When dry, it is a little slower riding than pavement, about one gear lower. It does retain most of its traction when wet, certainly much better than gravel which is a combination of dirt and stone. I don't think I'd go so far as to call wet limestone dust "quasi-quicksand". It's kinda messy and it slows you down, but that's all. Note that when it's very wet, say after days of heavy spring rains, it slows you down even more.
The bumps around Rochester can be a problem. They have recently fixed the worst of it, though ironically, that part is now torn up for highway construction. Caution, if it's a shady area and you have sunglasses on, you might not see them. (Except that some unauthorized person has marked them with yellow pavement marking paint...). Current status can be found at the Bump Report http://www.crazyguyonabike.com/doc/page/?o=1&page_id=332010&v=x. Note that despite the bumps, do use the trail through Rochester, NY Bike 5 is a bad way to go - busy and no shoulders.
Summary article here: http://www.crazyguyonabike.com/doc/?o=1&doc_id=9422&v=FM