Re: other DACs in the MHDT lineup. I have an Istanbul and I feel that it’s a real sleeper in their lineup. I love it, using the 5670/6920 converter and a 1970s West Germany made Siemens 6922.
FWIW, in. my application switching to the 6922 didn’t make the DAC warmer, just "spicier", for lack of a better way of putting it. Gave it a bit more of a forward orientation. For me, I really like it, although I could see others preferring the more laid back presentation of the 5670.