Our overnight train ride from Barcelona to Madrid on the Estrella train wasn’t too bad. At least it wasn’t the “circle of hell” one online review described it as. It was definitely a plus to have a bed to lay down in, as opposed to sleeping in a chair with your suitcase as a pillow, but there were six bunks to cabin, so you couldn’t even sit up on your bed. Plus, after piling all you luggage onto the foot of your bunk, there wasn’t all that much room for your body.
But it was ok, except that one of our bunkmates was an older, larger woman who kept mumbling and bitching about everything. However, in the end, I did get a few solid hours of sleep.
In conclusion, I’d say the overnight train from Barcelona to Madrid is a totally acceptable option for travelers to cheap to pay for the AVE train and who want to save money on one hotel stay.
Luckily, even thought we arrived in Madrid at the ass-crack of dawn (7 am), our hotel let us check in extra early. Nap time!