Even Jason suggests the Bifrost 2/64 is a match for the Iggy.
Do not overlook less expensive units. Of everything I have had in my system, my cheap JDS Atom+ has been the best overall. ( $99) I too am looking at the Enyo (Aries with new price) Mojo II, Qutest, or maybe a newer top line Delta Sigma like the SMSL DO300, Topping, Gustard X18 etc.
My focus is 90% on female vocal smoothness. Don't care about bass "
weight" or some magical details in imaging and air that were not on the recording to start with. I focus on what I do hear reliably. There are a lot of expansive DACs, but are they really better than what you get for $1600? "$700? or even $99? Do we want "clean" or the masking from an R2R? Masking from a tube? ( Or do we want that masking to be in a preamp? Lots of choices.
Upgrade the power cord. Yea, a 49 cent ferrite on the cord and it is as good as physics allows it, if and only if you have an RF pickup problem in the first case which almost no one has anyway. I suggest spending the money on the DAC, not on magic.