I am loving all this information that is being shared here.
Jonathan, Thank you for your willingness to share your knowledge and insight.
As I stated earlier, if we could afford to swing the ABBA 3rd Rail F7's, I would definitely explore said option, but we do not need 4 powered units. That is just way overkill for us. However, IF 3rd Rail offered Dummy B's like they are doing for the E7's, then we may reconsider and might be able to swing the expense of buying 3rd Rail. The picture you are painting as it relates to detail and definition within each loco is mouthwatering. 
I'm a very visual person.
We would eventually like to own several sets of diesel locomotives, so that we could model various timeframes within the life of the Santa Fe Passenger trains from the 1930's and Onward, ex. E's, F's, PA's, & FP45's. And as much as we love running prototypical trains, we also have to be realistic about what we can afford. Thus, though I do not like to cut corners 
, some sacrifices will be made as it relates to the amount of detail we can afford/ choosing which products to purchase.
I greatly appreciate everyone's input that has been shared.
