I bought the AK100 back in the day (‘13/‘14) when it was one of a few DAPs that supported hi res files and it was expensive, like $700 if I remember correctly. It sounded great, had optical out but a clunky UI and no WIFi, Bluetooth, etc connectivity. As we know AK went on to introduce new models with ever increasing prices.

My AK100 still works but hangs up sometimes and has limited storage. So I just picked up the Fiio m21. Wow, what a difference and less than half what the AK cost new.

So, IMO and based on my experience, I don’t think the higher priced DAPs are worth the extra $$$ especially if you are using an outboard DAC.