They are RTR, No assembly required. And they aren't overly expensive, both the Dash 9's and the SD40-2's that I have gotten were right around $150@. The SD45's that I pre-ordered are Operator models (no rivet counters in ATSF) are around $100. They also offer detail kits for the modeler to bring them up to Rivet Counter quality. I don't know if grabs are on the Operator models, but the railings are.
Willie -- You better send me those CF-7's so you will have room for the SD's!