I'm typically using a size 10 needle for piecing and I like 2.0, my machine grumbles a bit in terms of speed at that setting (I want to go faster!) and we usually go at 2.1 as a compromise if I'm doing long strips. I usually use leaders and the small stay stitching is cut off, but it is nice like today I'm putting on a binding and that extra stitch density is great (so long as I don't have to take it out to correct it).
For quilting I'm using a 12-14 needle and I'm still learning what I like best with Bernie. My friend gave it to me just exactly a year ago now. I've used the BSR, I've used the walking foot, I pretty much always have the walking foot engaged during piecing too. Most recently I used the serpentine stitch for quilting for the first time.