Hmm, I didn�t see the option "native" in the config-program of my MS600. x1 and x2 are options I know... I need to have a deeper look...
My MS600 has a "direct" setting for the digital output, which outputs the digital signal at its native sample rate (with the exception of high res files with higher sampling rates than 96kHz, which are downsampled as Meridan can't handle these higher sample rates). Not sure if this bypasses other types of processing by the MS600.
My MC200 (the older 500GB option) only had 1X or 2X options. 1X downsampled 24/96 files and left 16/44 files alone. 2X upsampled 16/44 files and left 24/96 files alone.
You really need to try out the DAC options you are considering in your system, be it a 3rd party DAC or a Meridian DAC. Just like all front ends, DACs from different manufacturers do sound different. An 818v2 vs. a high end DAC from another manufacturer will both be fantastic products, but each will have their own "flavour" of sound, with one likely being a better match for your system and your ears. Like you said, the ears have to decide.