It is a long ride, but a very scenic one. The train follows the shore of Lake Champlain for miles and miles in addition to the Hudson running that all trains between New York and Albany enjoy. The line does not host a lot of freight traffic so the train is not really subject to a lot of delays.
The border inspections take about an hour and the track for the first few miles over the border in Quebec is really slow, but both of those are allowed for in the schedule.