I have a 2 year old A17 and I have auditioned both the A25 and A35. I could not hear an audible difference between my A17 and the A25 and subtle differences between my A17 and the A35. However, with my A17 stacked with my Fiio Q1 via HO I found virtually no difference in sound quality between my A17/Q1 and the A35. I suspect the added power of the Q1 helped to overcome the differences between my stack and the A35. As a result I decided to pass on the A35 as I also didn't want to lose 48 GB of storage and AptX support for no real gain in sound quality. But I am finally going to upgrade to the A45 since AptX has been added and AptX HD is also supported. I think that the extra power from the A45 will allow me to retire my Q1 and use it as my computer DAC/Amp.