To be fair, the Primus line has gotten very good reviews for years from different publications, including Stereophile. As for the 160, IIRC Stereophile found it to have a ruler flat response. However since then Harmon upped the treble and bass. So the newer models should sound far from dull.
Ruler flat response does not mean they sound good. Hopefully the newer models sound much better. I have learned to be mistrusting of reviews as many reviewers try to be nice and write positive reviews on all the gear they review.