Sprinting, catching up, descending, cornering, I'm in my drops.
I don't really like staying in my drops long if i'm not doing any of the above, I'm more comfortable on my brake hoods when my arm is at about 90 degrees.
But descents are really fun in the drops, and I notice that when I'm in the drops I have better control of my bike, and I tend to stay in my the drops the whole descent from some mountains I climb, which is about 6+ minutes of descending.
I actually try to get as aero as i possibly can, as long as i can pedal.