Just got an open box Onkyo RZ840. I am upgrading from an older Sony 5.1 receiver. I have Sony LCR speakers and 2Polk in-ceiling for rears. I also have a BIC F12 sub. I also has a Vizio 60 inch HDTV. I was happy with the setup...But....I got a good deal on a 4K 65" LG. Then I started to get the itch. I got the Onkyo from them for 50% off open box. It looks brand new...Not even a finger print. I can believe the difference. It is like I never heard the other speakers. Much louder and clear. Now I need to upgrade the speakers. Maybe 2 more in or on the ceiling, new LCR, and 2 rears. I am happy with the sub so I may get another one.