I have already done this with one of my DCX2496's, but only ran the critical circuits (ie: entire DSP circuit, ADC/DAC chips, DEXA clock) off a optimal battery supply, whereas this device on your link is meant to run the entire unit in the car (via DC-DC conversion). If one is using the DCX with the analog inputs/outputs, you have to have positive voltages and negatives voltages to power the opamp circuits (ugghh...)(the only way around this is to passive transformer couple both the analog inputs and outputs, this sounds the best to me), and if the unit is modified to be 100% digital then no negative voltage is needed for example also.
For the house, the direct circuit battery topology would be the best way, but with the car this product on your link will be suitable, given the environment. In the house and in a high resolution audio system, I would rather have a clean optimal battery power supply feed direct to the circuits directly then have a product with DC-DC conversion to generate voltages with additional regulators. This is one my downfalls of car audio amplifiers is the DC-DC conversion generating 40+vdc from a 12+vdc source to power the mosfet rails as DC-DC conversion is a noisier way to generate higher volts or additonal voltages in comparison to a full blown linear AC to DC power supply, but it works.