The ATS question is interesting. I don't recall ever seeing a ATSF/BNSF freight train with ATS, so it is apparently only required to go over 79 mph. Remember years ago when Santa Fe ran a huge business train out of San Diego? I watched them install the ATS shoe on the lead FP45 in San Diego and can tell you there was no chance of keeping up with it once they cleared Del Mar obviously doing every bit of 90 mph. Of course if there was a fully functioning PTC system this wouldn't be an issue. Tick-tock the end of the year is fast approaching. Is there any large territory that has fully implemented a tested PTC system or as of January 1 is everything going to grind to a halt or FRA fines issued? (I think UTA might have installed it new, but are any of the new mandated installations in daily use?)

The gear ratio and maximum speed is the biggest question. I'm not sure it is that big of a problem except on the south end of the surf line assuming they are operating at 79+ mph. I would expect to see a regular Metrolink engine on both ends, which may create a tighter power situation.

The BNSF engines won't have the door circuits, and I don't remember how the door circuit loops back. There is an override switch that is commonly used.

What will be interesting is how to deal with the blended dynamic brake issue. I assume Metrolink will use the BNSF engines under power instead of dragging them around as dead cab cars. As I recall the GP60/B40-8 are equipped with 26 or 30 air, so it will take so effort to retrofit them with blended brake. Weren't most of the GP60Ms rebuilt with standard control stands? If they were retrofitted with CCB/EPIC then it may only require a software change. If they don't deal with it, the engineers will have to quickly figure out how to get the engines to play well together without blowing the station stops.