The adulation for MM is about more than just the ride system. It is about the extremely skillful integration of AAs, screens, music, and other elements and an overall sense of the classic “Disney-esque.” Rat is a screen ride and is in no meaningful way MM-esque. From all indications, RotR is akin to or perhaps even superior to MM. MMRR may or may not be in the same league, depending on the final product.
In any case, I’m excited for all three rides. What’s more, I don’t see much complaining on here about any of them, save for the boneheaded decision to tear out a classic dark ride for MMRR, which is not a knock on the potential replacement.