I'd suggest packing light unless you are a weight lifter! Thankfully I only ever had an overnight bag at most with me when I travelled by train recently in Morocco. What I discovered:
- There are no escalators or lifts at stations so you have to lug luggage up and down stairs to access the platforms.
- You may be told at very short notice to change platform. (This happened to me three times out of seven.)
Many people will just track hop - this is not advisable but even one of the railway staff herded a group of us across the tracks at Casa Voyagers. It was hard enough for me to get down from and back up to the platform without luggage. It would have been impossible for me if I'd had a case.
- The steps up into the train can be narrow and steep. There may also still be a wide gap between platform and train steps.
- 2nd class carriages were perfectly comfortable enough but came in different styles: compartments of 6 or 8 seats - limited luggage space other than over head; normal walk through compartments with seats 2 x 2 either side of the aisle - some of the carriages I noticed luggage areas near the doors; double decker trains - more steps to negotiate.
- Most of the trains seemed to have a small buffet carte go through the train.
- Toilets: On the train - I didn't explore; At the stations - on the track side of the doors not in waiting room areas. The couple of times I used them they were cleaner than I was anticipating.
Overall experience on the trains was good and I would use them again - but not with a case full of luggage if I could help it.