What was really interesting to me last night was ABing 16/44 converted from DFF file via Saracon at a mate's place through SGR actives similar to mine.
The differences were very small through the Mytek direct to the CX3's (I have CX4's)
Which is to say I thought I could pick the difference reliably but my friend wasn't convinced.
It might have been my psycho acoustics going on but the real point to the story is the differences between the formats, if they exist, are very small. It wasn't a "OMG that's amazing" - more like "I think something's different - abit toppier, abit more bass...etc".
And you know what they say in audio - if you have to think about it then it likely doesn't exist.
So what I deduce from all this is that what really matters is the source material in the first place. Not whether its 1/352 DFF or 16/44 red book.
What I also posit is that perhaps more care is taken with SACD than with standard red book - dunno.
So word to the wise - don't worry about DFF just yet. It may all just be fluff and stuff.
On the other hand the Mytek impressed with its abilities for a $1600 dac/pre amp - red book or dff...
Best Wishes, Andy