Saw this earlier, but had to get home to take pix:
Here's a comparison between RailKing and Premier ES44's.
All of the side-by-side shots are lined up by the rear couplers.
Hopefully this will give you an idea of how the two would look together.
Personally, I have two Premier ES44's in two different MTH colors and the Railroader Club RailKing ES44 / SD70ACE. Why? beyond the "company colors", I thought it'd be neat to have both a Premier and a RK set of 'company colors" units in either/or service pulling what should probably be considered a complete set of the York boxcars.
---PCJ