Correct me if I am wrong but the DX100 was designed before the 2M version of the Sabre chip was released. Today Hifiman would use it as will all DAP designs using the 9018 chip moving forward. (See iBasso DX90...) There is no reason to have 8 channels (i.e. Dolby 7.1 support) in a stereo DAP. There is also no reason to assume that the 2M chip will burn less electricity than the regular chip running just two channels.
As for battery life, that "absolute minimum" would be decoding 24/383 DXD files. I don't have too many of those yet. 10 hours for more common files seems likely which puts it on par with the DX50 which has a Galaxy S3 battery - also 2100 mah. This is the point that is being missed in some of these criticisms: the Calyx M is incredibly thin. It's battery life is going to be limited by the size of the battery given the intensity of the electronics.
These guys know how to use the Sabre chip. The OS looks to be the best yet on any DAP: Rockbox-like active playlist control with a beautiful color interface and unprecedented high-res support together with insane THD numbers.
If the SQ is what Calyx are capable of, It looks like an absolute winner to me.