I would have thought it would be longer but the average seems to be 65 minutes with the long 73 minutes. But there are only 3 trains before 12:00 with one of those at 5:15. The next set of trains is between 15:00 and 18:00 with 4 trains so the schedule is rather limited. The round trip Amtrak fare would be $164 for near rush hour trains, and between $100 and $138 for the other options. To me this does not seem like a good price but to each their own.
My other point is I would view this like I would view a flight with a connection, I would avoid it. I would still look for non-stop flights regardless of carrier instead of doing this to stay on one carrier.