I have what I think is now 2 generations older, the 507ux. Fabulous performer with normal speakers (i.e. min impedance just around 4 Ohms, or a bit lower).
I found it significantly better than the AR SVi75. Extention at the top and bottom octaves, and a mellower, sweeter midrange. The Luxman sounded more like tubes to me than the SVi75 in terms of mid to treble output.