Those ugly step sisters
Bridesmaids of the rails.
For the most part, (back in the day) an entire freight train always got a wide-eyed notice, until the caboose went by.
It was more-or-less only a signal that the fun was over.
Car spotters looked for their favorite billboard boxcars and road names, detail purists scouted the train for anomalous oddities, and photo bugs clicked away at a fever pitch.
But then the caboose went by, and everybody turned around.
It's kind of the same way on a model layout.
I'm a caboose fan. Ever since I was a young boy I've been enamored of them. The other kids in the hobby all seemed to ignore them, as though they were only necessary to complete a set of something, like dishes.
My era layout will have at least one yard track devoted to them. Each caboose has it's own special place and time for deployment... for even incidental or minor purposes, e.g., deadheading ('tail wagging').
There are two to four cabs each of four different railroads serving my operations, and each one has a place in the scheme.
I didn't spend a lot on them -- they're all low to mid-priced models, but each one is tuned to roll, and (in one way or another) is treated with the same attention as any premium car.
Proto... Athearn RTR... Centralia... MDC.