Re: What's the deal with stick size?
I think to a certain extent it's both a "right tool for the job" issue, but also (and I think mostly) a function of matching the best stick to your hands and playing style.
I used to follow the idea that quiet music needed smaller sticks, but it just didn't work for me. I found trying to adjust my technique using an SD4 or 7A for lighter music just led to a series of compromises that affected my playing. Once I found a stick that was truly comfortable I really have no issue playing loud or soft, fast or slow because the stick responds to what I want to do with it.
For me, it took a lot of looking at a series of sticks before I found what really worked. Trying sticks with a couple hundredths of difference in diameter here, a 1/4" of length there, just dialing it in stick by stick. I felt a little like Goldilocks at times, but whatever works...