From my testing, I've found the clip indicators on the MT to be very accurate, and the clip indicators on the SBM1 to be not so accuarate, depending on how you look at it. I tested the MT against my V3 and my home Sony A6 DAT deck, both of which I've found to be very accurate. I then looked at the waveforms in CoolEdit. Each time the MT indicated an over, so did my V3 and A6, and the waveform view showed that to be the case.
I guess you could say the SBM1 indicators were accurate, but from all my testing, the clip indicators come on exactly at clipping, not at -2db as advertised. So from my testing of at least my SBM1, the clip indicators of the SBM1 came on at 0dbFS, not -2db, and they seemed to be a little sluggish at that. Bottom line, I trust the clip meters of the MT more than the SBM1, and they seem right on par with the V3.