Well I’ve experienced the “pre flight dining” twice, first out of ORD & then out of IAD. Both times I would consider the offerings & atmosphere of the experience to be nothing short of appalling. In IAD I ended up having about four bowls of soup & bread rolls, as everything else looked inedible.
In fact if I were ever to do a sleeper service out of IAD again, I would eat at one of the main airport restaurants before going to the Terraces & forfeit the pre flight dining altogether. In fact on the night in question, I remember looking enviously at the people eating in the restaurant just outside the terraces. This is not what I would expect from the premium offering of a major airline.
So I would agree entirely with the OP in his summing up & also would agree with a post I read in another thread where the Sleeper Service was described as “Rip off Service”