I used the DXI350's.. ended up taking them out tho.. The fill wasn't worth the disturbance to the soundstage. I assumed going into my build that Big's view on soundstage and not using rear speakers was crazy, but I have to admit that he's 100% right. I found zero benefit to having them
Anyway, I've still got my DXI400's and DXI350's for the time being. They're boxed up and ready to ship back to Crutchfield.