Seems to me, especially with such a short barrel, there would be higher velocity, and less recoil with a 115 grain projectile than the heavier 124 and 147 gr. bullets.
Question to those that have tried different weight ammo:
-Is there a noticable difference?
-What do you prefer?
With the caveat that felt recoil is highly subjective, I seem to notice a greater recoil with 147-grain bullets in my R9 than with the lighter loads.
Subscribing as I do to the "bigger rock" school of thought, I used to load my R9 with 147-grain loads. However, in an attempt to simply my life, I've transitioned down to 124-grain since my HK P7 was designed for the 115/124-grain NATO rounds and can have the timing of its gas-delayed blowback locking system thrown off during recoil from the heavier load.
As for brand, everyone will develop his or her own preference. I personally am an admirer of the Remington Golden Sabers, Speer Gold Dots, and Winchester Silvertips (all expanding hollow points) for defensive use and Winchester "White Box" FJM for range work.