Xiaomi Mi Note/Pro has a similiar soundprint as the X3II, but the X3II has a wider soundstage and much cleaner sound, especially at high volume.
That phone is old and not worth buying for the sound or for anything else. Same goes for Meizu pro 5/Pro 6.
I also don`t understand why anyone would recommend Meizu`s or Axon`s, when phones like the HTC10 are going for around 250€/$ right now. Meizu Pro 5 is an outdated phone,and the SQ is inferior to both the HTC10 and the V20. Same goes for the Pro 6, which sounds even worse with it`s shrill highs and lack of bass. You will also never see any useful updates for those phones, especially not from Meizu.
The HTC10 runs circles around any Meizu and Axon when it comes to SQ and is also a better phone. The V20 is also an option and can be bought for the same price right now. I prefer the 10 for the sound, but if you have gear that needs much power, V20 is probably the better option. But no matter how you turn it, they`re both better than the Mi note pro, pro 5, pro 6 or axons.