Another reason why Metra likes these (probably): being in a reasonably good area for air quality (ummm ... WINDY city ...), they can get away with buying something that's only Tier 3 emissions - because used. Which means no DEF. Care and feeding much easier and fits in much better with the rest of the beat-up old fleet. And the flacks are right: going from Tier 0+ (or worse) to Tier 3 is a huge emissions improvement, plus the newer power (at Tier 3) gets better "gas mileage" than the really old stuff. Overall, an interesting but good move for Chicago.

One might wonder if such a big, heavy locomotive with C-C trucks is a good move in passenger service. For commuter trains that seldom exceed 60 or 70mph, and have lots of stops and starts, it's probably OK as long as there aren't a lot of sharp curves to negotiate. Better adhesion than B-B and more starting and dynamic braking power. And they did have those F40C's, right? The size, of course, will probably lead to amusing pictures of off-peak 2 or 3 car trains where the locomotive looks like 1/2 the length of the train from certain angles...