Just curious. Metrolink in LA seems to be the only place that has ever bought, and is operating, the F125. Is that in fact the case? Considering their teething problems, are they reliable-enough now? (Seem to be, as all have been accepted and are in use.)

...

Answering most of my own question: yes, Metrolink was the launch and only customer for it. Apparently MPI (before being swallowed by Wabtec) also offered a MP54 variant that was Tier-4 certified, with (like the F125) only one buyer (GO Transit). Everybody else getting Tier 4 passenger locomotives in the US has bought Siemens. Thank you Wikipedia (F125, MPXpress).

Unlike Wabtec (MPI), Progress Rail still lists the F125 on its website. Theoretically, they could build some if you want to pay for them. However, they focus more on rebuilding older & freight locomotives for passenger use, and parts supply.

Kind of leaves Metrolink in a bind, even if they have enough to cover current operations; if they need more locomotives (which they will, someday), it might be difficult and expensive to get more from Progress (i.e. ramp up a new assembly line). But getting Chargers like everybody else (to a first approximation) has would introduce maintenance complexities with different engines and mechanical systems. Could get interesting if they want to (or need to) add trains to serve Brightline. Wonder if BlW might consider chipping in to wire the line between Rancho C, Union Station, and the shops, and buy some electrics or Siemens Dual-Modes for that?