Performance wise the X4500H will have slight upper hand, although if adding power amp.. And the automatic YPAO setup doesn´t do much of any subwoofer eq correction. Manual PEQ for sub reaches around 31hz still? To be able to get down to 15,6hz you had to use better microfone with REW cause the YPAO mic has some limitation.
Let´s hope the new sexy 2020 Yamahas will come with improved YPAO as many people are not happy spending big bucks for the machine and end up with boomy bass, where as XT32 with Denon is much better.
Audioholics measured A860 and X3300W, Denon was ahead (better behaving with 4ohm loads, preamp out measured better etc). X4500H/SR701X bumps the power output slightly at 8ohm, but also for 4ohm load from 2ch 140w 0,1% THD to around ~200w, so i think this is very much sweet spot for many. Also if you read the article you notice how Yamaha has done some compromises to get the features in. The powersupply was smaller than 2006 released RX-V659 plus the caps were lower rated aswell. So 900$ machine had poorer internals than old 400$ one. The better quality with Yamaha starts with 1000 serie upwards, ideally 2000-3000 serie should be looked as they bump the poweroutput quite noticeably, better DACs etc. You need A3070/80 if 7.2.4 is the aim.
The Yamaha AVENTAGE RX-A860 7.2CH Atmos/DTS:X AV receiver is packed with excellent networking features but it does fall short on power delivery making our recommendation conditional based on usage.
www.audioholics.com