To me, such disappointment would likely apply to most integrated amps people talked about on this forum. I am sure I missed a few but I am not aware of too many, may be just a few, integrated amps that have a flag ship DAC chip onboard such as Sabre's ES9018, 9018, or 9038, AKM's AK4490, 4493, 4497, 4499, Cirrus Logic's CS43198, TI1794.
Denon, Onkyo and Yamaha's flag ship AVR, and Marantz flag ship AVC do have either near or ex flag ship AKM or Sabre DAC onboard.
If someone mentioned this on forums, integrated amp owners (some sensitive ones.. would typically counter the importance of implementation. Surely implementation matters, but if the implementation schemes are typically better in expensive integrated amps, why not go an extra inch to "implement" at least near flag ship DAC chips in an integrated amp?