They are two different things. The x6 is a smart TV box and the x9s is a media player. Obviously the x9s will be better as it can do so much more.
Almost the same usage. But there's no competition regarding to performance. X6 : CPU RK3368 < X9S : CPU RTD1295D
a more fair comparison would be x6 pro vs x7 or x8 (x8 is a baby x9s) , in witch case again, x6 <x7< x8
Nobody never talk about Zidoo A5s... It's a really good little device with a lot of possibility (Libreelec)... But, excuse me, I out of subject. It's juts because this device seem to be the black sheep of the family... I had pity on him