I also used a MDF for several years. I was always worried I would wake up my apartment neighbors. I am not sure about the Rocky grinder. I upgraded to a Ceado grinder and I can vouch that they are very very quiet.
I have a Gaggia MDF and the noise is making my household crazy. I have a Silvia ( with a DIY PID ) and roast my coffee. I'm pretty happy with the grind of the MDF, but would like something quieter. I've wondered abou tthe Rocky. Thoughts? Thanks