And I am sure they are great products. I just felt betrayed and ignored as a loyal customer, so they could move on to android, and they never looked back. Again, I don't hold any real grudge at this point. I have just found that for the money to sound to features ratio, iBasso has been better for my wallet than Fiio (except maybe those UTWx, which I really would like to try sometime hehe).
Don't be scared off. Don't listen to me. I am ranting about something that happened many years ago. Fiio could not stand among the top DAP makers if they weren't doing something right. You will never know until you try. That is half of what this hobby is about (experimentation with the goal of top sound to your ears).
Remember that with planars knowing the impedance and sensitivity doesn't help much. Having lower impedance, and high sensitivity (with planers) only means that it can run on anything. Having more current (not voltage) available will drive them to their full potential. The problem is that nobody knows what that magical number is because the headphone/IEM makers don't release amperage requirements (because all other speakers don't need to give this measurement). Plus, if they release this information, even at cheaper prices, less people will buy them thinking they need a higher-powered amp to drive them. They want to sell them to the masses...
But you are right, they might not get fully driven with the AZ09. I remember when
@miserybeforethemusic did a test with the iBasso CF01 and the Tinhifi P1. They could be driven with the CF, but there was barely any headroom, and it was definitely not to their full potential, as was shown by him listening to the same stuff through his A&K afterwards. Good Call!