I used the sifter shortly after it came in the mail. I think that 40 and 60 are good for making whole wheat bread. The 60 sifter takes longer than the 40 to sift through a given amount of flour. If I wanted it finer I would just start with the 60. Using a 40 followed by the 60 requires you to make more transfers of the flour and you will need to change the sifter in the middle of your sifting.
The machine is very quiet with exception of using the lid. The lid rattles and makes noise, but I felt like there was no reason to use the lid--there wasn't a cloud of flour produced. I found myself stirring the flour on occasion. The vibrating causes the flour to move to the center. Although, I don't know if this was necessary.
I plan on using this as often as I grind flour.
I gave the price "3" because 8 days after I purchased it, it went on sale for $100 Less. Ouch! I could have paid one-third the price! The moral of the story--plan ahead with your purchase, sign up for email sales and check it regularly, and wait a a few weeks before buying.