Finally back up and running (though the cabinet is currently in pieces).
Here are some pictures comparing my new marquee to the old one.

Source image

Unlit
Top to bottom - ClassicArcadeGraphics, EmDKay

Lit
Left to right - ClassicArcadeGraphics, EmDKay

Note that's direct sunlight, but it really does give an accurate representation of the relative print quality.
Major differences: EmDKay marquee does not appreciably wash out when backlit, is much closer to source file's color (particularly in areas of darker blue), and does not suffer from the extreme color banding in areas of gradation that the ClassicArcadeGraphics one does.