For me the attraction is that I've always liked the utilitarian look of "hood units" like the early SD and GP diesel-electrics, and between the SD7 and SD9 my favorite road (SP) had a pretty sizable fleet of them (43 SD7s and 150 SD9) that mostly saw use hauling heavy lumber trains between Northern California and Oregon. They were nicknamed "Cadillacs" by a number of SP's crew members because of their smooth ride.
Of note is that after a major fleet rebuild (GRIP), two SD9s (#4450 nicknamed "Huff" and #4451 nicknamed "Puff") were reassigned from freight duty (exception of 4450 which was assigned to the snowfighting fleet on Donner pass at the time) to the San Francisco-San Jose commuter train, both of which I believe were the only SD9s that retained their steam generators after the fleet rebuilds. They were known as the cleanest looking SD9s in SP's entire fleet (because of their commuter duties that kept them constantly in public view). Unfortunately #4450 was scrapped in Portola back in August 2013 after it was determined the amount of rust cancer she had and other mechanical issues deemed her unsuitable for a rebuild, while I believe # 4451 still exists under ownership of the Northwestern Pacific railroad which she was sold to many years ago, although from what I understand she's still mothballed, sitting very neglected amongst several other derelicts, probably will face the same fate as #4450 if there's no attempts to preserve her.
