There really is not a negative. I've printed a whole Elevated Section (uprightes and girders), couplers, and many other non-train items). When getting a machine, keep in mind:
The print platform (mine is heated aluminum using painters tape and glue sticks and I sometimes have issues with the first pass sticking). Some say glass is better (which I want to try at some point). There are lots of options that can be purchased.
The material - most use ABS or PLA. Now resin is growing and is a good option
Is the printer enclosed? While not super important, having a heat controlled area is a good option (mine is)
What is the size of the platform and how is it heated - you will see in picture two below that I have a heat issue with mine which causes the bowing.
One other thing to keep in mind is the printer software. I don't use the one that came with my printer - I use Simplify3D which is really good (and recomended to me from a friend who is a designer).
Here are some of my prints (train and not):
Passernger cowling
Printing the uprights:
All put together:
I'll post more pictures from my phone as this is my computer.
