Hi, bed is comfortable enough, you have to share compartment with 4 people but it is safe. Bathroom is only a toilet, for most of the train it is just a hole in the toilet pod, new ones has nice bio toilets. No shower.
It is ok ride for short trip but I would take it for 4 days like Moscow - Irkutsk.
It's OK. In summer they run an additional older train which may be in worse shape.Edited: 01 February 2018, 18:52
If you are traveling on Sat. or Sun. you can arrange other type of train transport. Search forum for the recent post on "Chudovo" (w/o quotes).