They made my trip more stressful, not less so.
I booked with Rail Ninja long before my trip. I started to get nervous two weeks beforehand when my tickets still had not been sent to me. I sent an email and they told me they did not know if they would be able to book me a ticket or not. When they eventually got back to me, I had to accept different seats at a different time to the ones I requested. Nobody apologized to me at any point. Please save yourself stress and do not depend on this company.