I also got recommendations for the 6xx due to it being on sale. Is it really better? I can't find the sale on amazon, but on drop.com it's less than 194$ (including 15$ shipping), very high chance to get charged local tax another 33$, and depending on the shipping method they use additional 0-40$ handling fees, so total 227~267$. 560s on Amazon is $180 + $53.59 shipping and tax, paid in advance (so no surprise fees, but also no chance to evade tax), for 233.59$ total.
Again, the main goal is getting the best possible virtual surround effect, probably with the G6 or GC7.