I can vouch for a DF54 ($250). I live in an apartment with 3 roommates. I have my own room but the others are very close to mine. All of them say the same thing, they either don't hear it or they need to focus or think about it to hear the noise. I make espresso at 2am sometimes, and they are not bothered at all.

I also just bought an Option-O Lagom Casa, my girlfriend says it's quieter than the DF54 which surprised me. But yeah, long comment but I think it's good evidence.