I get the impression that DMUs are being touted (in this case) by SMART because they are perceived as a fresh, new solution to the area's transportation needs. This in turn probably stems from the pronouncement of consultants and Colorado Railcar's promotional materials. America likes things that are new and different, and the tried-and-true old stuff (regular passenger trains) would never due for a shining new era in transportation. (Look how "light rail" is frequently held up as a solution for all sorts of transportation needs by those who don't even know what it is or understand the sort of environment it is useful in (urban areas with frequent stops and high frequency of service).) The "sprinter" railcars in Oceanside are essentially dieselized light rail vehicles, and they operate in a "light rail" environment, minus the electric overhead. It seems to me that the Colorado Railcar DMUs are cast in the same mold, just larger and heavier to make them mainstream railroad-compatible. Historically, railcars were used on lines that had light patronage and little service (RDC use on the Boston & Maine and the New Haven being examples to the contrary); if SMART is really thinking in terms of heavy commuter patronage, I would think that DMUs would be both inefficient and expensive compared to regular trains. With proof-of-payment fare collection, even a multi-car consist would have a crew of only two (like Metrolink, Coaster, etc.) Also, given Colorado Railcar's past performance, I wonder if they could actually deliver the goods--I was kind of shocked when the first of those cars for Portland actually turned up.