be nothing (much) to write home about
To be not especially remarkable or noteworthy; to be rather dull, mediocre, uninteresting, or unimportant. A: "Have you eaten in that new sushi restaurant yet?" B: "Yeah, I went there last week. It was OK, but it's nothing to write home about." His performance has been nothing much to write home about so far. To be honest, we were expecting much more from him when we recruited him.