I typically don't have issues with water retention, even when using wet compounds. I've taken a metric shitton of anadrol over the years and have never had issues; same goes for trestolone and HGH. I actually didn't know that tren had that side effect for some people, and I've only experienced the opposite with tren: it makes me drier.
To answer your question, primo has a drying effect on me, but I'm apparently the wrong person to ask, since water retention is never an issue for me. From anecdotal evidence that I've read from others, I've noticed the same trend: it's a dry compound for most, which makes sense due to it acting as a competitive inhibitor of aromatase.