I was happily reading your post and nodding and saying "yep" until I reached your bucket size and my eyes bugged out!

For a single figure I render with a bucket size of 256.  For scenes, depending on what is in it I tend to go lower, 128, 64 and sometimes 32.

The key is denominations of 8, with 8 being the smallest.  

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi