I have been successful 17 out of 18 times on A/C with a F/C Cabin. On 2 of these, I was pulled up from my coach seat.

On my 7 segments on RJ's or Turboprops, I am 7 out of 7 getting my favorite seat.

I too have found that the F seats are usually not open at the 3 day window, but do open up either 1 or 2 days ahead of flight time.