I always wanted to try flats on my Millennium but sadly sold it before I could. I always struggled with the zingyness and super hi-fi sound with rounds on it. The last strings I had on it were Cobalt rounds trying to coax some more girth out of the sound but I don't think they ever settled down enough for me. I almost always use Chromes on my other Peavey basses with flats and they sound awesome. That said, none of them are active. I think Chromes would be a possible very good fit on the Milly. Sorry I can't give you more.
Thanks - that's kind of my thought on it too. I may just have to be the guinea pig

