It would be a mistake to ever purchase another expensive foreign train set, as the benefits of such a purchase are very limited.
Looking back, the Acela Express does not represent a meaningful advance in service in comparison to the conventional locomotive hauled, conventional Amfleet coach consist "Metroliners" that immediately preceded it.
Obviously, there is a place for extra fare, express services, but looking at past experience, there is nothing to be gained from TGV-style, tilting trainsets, which are expensive to buy and service, and invariably problematic in service. Somehow, I doubt that passengers would have paid any less to ride in further renovated Amfleet coaches drawn by 125mph locomotives, than in the Acela Express trainsets, which in any case are capable of only 150 mph bursts in limited intervals, not enough to make much of a difference in overall schedules. The Acela Express should be the final example necessary to deter future boondoggles in highspeed rail that end up being on marginally quicker than the existing conventional rolling stock, despite being less reliable and flexible in service.
Far more could be gained by eliminating the bottlenecks in the current right-of-way through infrastructure spending, and concentrating on reducing dwell times, than in spending huge amount on further embarrassments. Now is the time to improve running times through signaling, track, and station improvements, while improving service outside of the NE Corridor by giving passenger trains real precedence over freight trains on non-Amtrak owned trackage.