The phrase "complimentary things" is correct and usable in written English.
It is typically used to refer to things or comments that are kind, favorable, or that praise/flatter someone. For example, "His mother always says complimentary things about him whenever we see her."
He's said some complimentary things about Putin.
And Shane Mosley would say only complimentary things about the man he defeated.
Indeed, he said only complimentary things about Powell's predecessor, Janet Yellen, whose term of office ended in January.
He has a few complimentary things to say about Ms. Winfrey, but his section about her amounts to a comprehensive takedown.
But the principal flutist of the Chicago Symphony Orchestra had some less than complimentary things to say about the Los Angeles Philharmonic, according to a newspaper report.
[His questioners] were convulsed with rage because Mr Galloway had said complimentary things to Saddam Hussein and Bashar al-Assad when he met them.
"There's a complimentary thing about transparency that is, it's not just about agency — it can't be a black box.
Camp-following fans claimed that Martin had said the same complimentary thing about San Francisco when they played there the night before.
"And then it very beautifully turns into the other, complimentary thing, which is that you understand the person better by virtue of the song, and it's a lovely sort of virtuous circle that this is.
About the only complimentary thing that could be said about the idiotic defacement of the 7 July memorial, on the eve of the ninth anniversary of the bombings, is that the vandals had a sense of architectural context.
The most complimentary thing you can say is that these properties no longer are overpriced.
