I guess it all depends on what you are trying to protray in your photograph. I break down railroad photography into two categories - photos about railroading and photos about railfanning. Personally, I prefer those with an emphasis on railroading, as it is what I am actually interested in. Let me explain.

While some railroad photographers have some formal training, the vast majority do not. They learn by doing. They learn how to operate their camera effectively. They learn what my college photography professors referred to as "technical" photography. The really good ones and generally those with formal training learn the artistic side of photography. They are not only able to capture the subject, but some sort of emotion with thier imagery. Those who have not gained this skill simply focus on the subject, and miss the forest for the trees. Those who are able to capture the emotion behind railroading are those who I classify as photos about railroading. You look at their photos and feel the picture, not simply think "hey look, its a train." Those who focus on simply the train itself are what I classify as photos about railfanning. This is because it captures someone's love of trains, not a love of railraoding.

So, getting back to the question Steve posed, I am inclined to prefer the photo with context. If I am looking for a detailed photograph of a locomotive for modeling purposes, great. Otherwise, a photo with context is far superior.