I have the MiMi and it's a little noisy, but nothing too loud. It's not something you'll hear through a closed door, and a blanket dampens most of it. Either way, it's powerful, waterproof, and the sound is not distracting!
I was curious which was a better option in noise level and strength.
I've been planning to get Bcurious, but worry about the hard plastic, non squish and the vibrations. Mimi is not a toy I'd ever spen $ on since the vibrations are said to be weak. However, Matryoshka and Zini Deux are my next purchases... Just waiting for them to be in freaking stock! I'd recommend checking out those before shelling out the $ for Mimi and even the lovely Bcurious.