The MP54s were specifically designed with the possibility of operating shorter consists with only one of their two prime movers online. This saves a humongous amount of fuel for service versus using both prime movers or the MP40's single 16V-710.
They did have a rather protracted development term, and did have a bunch of peculiar failures early on that had to be remedied by Wabtec, but are now operating quite reliably. Their biggest issue is that they are quite loud inside with both of the engines on, and that has resulted in several crew complaints.
Dan