In the past year there have been several extremely positive reviews on the Topping D90 SE/LE and Gustard X26 PRO DACS. All reviewers stated emphatically either of these two DACs were as neutral an anything they have ever heard. Granted around here neither of them are expensive enough to be considered for anything other than a paper weight, but you might be surprised based upon what I’ve read.
FWIW, I've owned R2R Ladder DAC's and at least the ones I've had were anything but neutral. I grew tired of their presentation quickly because quite a bit of detail and imaging were left on the table. Its not a road I would want travel down again.