A 3B prop works very well if you have a slow flying style. It is easier to control the power and speed. For a fast and big flying style you will use a lot of mAh compared to a 2B.
I used to fly 3B with a Pletty Advance powered Wind S Pro. Due to the low drag model this combination worked really well. My favourite prop was the PT Model 20x13 3B. Ulsamers 20x13 3B was to small/ didn't have enough trust. Mejzlik 20x13 3B used a lot of mAh if i wasn't careful with the throttle.
I have sold the Wind and prefer 2B on my other models.
Regards,
Henning