Hi
I have the first Photon Ultra, and love it's detail, does it do things better than my old creality halot? With my eye I honestly can't see a difference.
However having never to swap any of the inside out is a big bonus for me, like has been said, the build volume is quite restrictive.
This image is of an excavator printed on my ultra (model from someone on tinkercad) , I know its not a rail model but it is the same scale and for a quary area on my layout, as you can see there are some very thin parts that the printer copes with very well, have to take time removing supports though 😀