It's funny... the market is saturated with DAPs, yet still companies around the globe, large & small, keep churning them out, as if the market is infinite...
Sure, the number of potential DAP customers vastly exceeds the number of potential Digital-Transport customers - I acknowledge that, but that does not necessarily mean one should be pessimistic about how large the Digital-Transport market might be. It is growing, all the time, as more and more people expand their awareness of how flexible such products can be, and, frankly, I wonder how many people
accurately predicted how successful Oppo's HA-2, and Chord's Mojo would be, for example? (and Fiio's own DAC-Amp products, of course). Surely, in a world saturated with DAPs, it would be risky to develop and manufacture DAC-Amps like the HA-2 and Mojo? And yet they are exploding in popularity, selling in their tens of thousands. OK, so it's not hundreds of thousands, or millions, but tens of thousands is not to be sniffed-at, and definitely repays the R&D efforts made by the respective DAC-Amp companies.
So, I reckon whoever makes it to market, first, with a decent-performing Digital-Transport (with 2x SD slots, and lighter & slimmer than a similar DAP) will make their investment back, and more -
even if it doesn't make them billionaires!
...if Fiio get their act together, and release the T3 quickly enough,
just the mere fact of offering 2x fullsize SD card slots will, ALONE, make a huge number of people want one.
Fiio need to take the opportunity to play that ace-card before someone beats them to it.