Yes, you would be using the Panasonic's DAC's for TrueHD and PCM. I have no idea what kind of quality the DAC's are in Panasonic's Blu-ray players, but based on my experiences with DVD-Audio and SACD I suspect that it'd at very least be worth connecting the 7.1 analog and comparing with traditional DD/DTS over optical - the benefits of lossless are likely to be significant, certainly enough so to justify the effort of making the comparison with a number of different discs.