When I had it I calibrated the input/output levels so they were at unity gain, which unusually required to set the MK3 to -2 whereas on the MK2 it's perfect unity gain at 0. As for the waveform, I wouldn't test with on board processing of any sort enabled. Don't ever expect improvements across the board from one model to the next with most companies. The MK3 uses a different brand of converters than MK2 and I've seen that behaviour on many units using those converters. Most interface companies prioritize features over conversion quality because it sells. Gotta keep costs down and marketable features up.