Be aware than the upgrade portion of Acela F tickets are NOT refundable if you do not cancel the reservation at least one hour prior to departure - unless there is a schedule delay, and then there is some exception. Also, some fares (I have yet to find one on the Acela that this applies to) have refund charges.

http://www.amtrak.com/plan/refundpol.html

"Metroliner/Acela Express First Class Accommodation Charges: Refundable if reservations are cancelled at least one hour prior to departure. If not cancelled in time, the amount of the First class service accommodation charge will not be refunded, but may be applied to Metroliner/Acela Express First class service travel on another train on the same date only."