Basically: It's OK. not great, not bad. It's clearly a cheap accommodation, but the bed and bathroom were clean enough and the room was quiet.
Initially they could not find our reservation, but that was possibly a fluke. One chair and one set of towels in our appartement for two, but on request we got an additional set of towels without issue. Location is fine for exploring Metz, close to the train station and a 10 minute walk to the center.
Don't expect too much, but it's cheap :-)