Yeah, no. MMX7/8 are nowhere near the gaming atrocities that are Sonic 06 and Boom. They're not even technical messes. They're weak games but are totally functional and the only reason they're so divisive is because the franchise in general has a high bar. Which cannot be said for Sonic.
I think the highs of the Sonic series (Mega Drive/Genesis Sonic) are higher than the highs of the Mega Man series for the most part, but to suggest that Sonic even comes close to the consistency of Mega Man is... uh... something else.