I want extra channels so I can add top middle, but the 6700 also has dual speaker presets so I can have a setting for when it's just me watching, and another setting for when I have guests sitting in the back row. Also, the 6700 has bluetooth so I could use my bluetooth headphones when I want to keep things quiet if the wife is sleeping. DTS: X pro would be good too once I add the extra atmos channels. Another reason to upgrade is so I can replace one of my other aging Denon 1080p receivers with the 4300 so when I eventually get a 4k tv in the living room or bedroom, I'll be all set there. I don't really care about 8k, but maybe some of the other features will help with the next gen xbox but most of the time I'll be just using my sony 4k 285es, and I'm not sure that can take advantage of those newer features.\n\n\nOkay, and iiuc, you don't need balanced I\/Is, so the 6700 has everything you need. It also gives you the option to use some of the internal amps for the surround and Atmos channels, that prepros won't.