Some people notice a difference in recoil, some don't. Probably really depends on the gun. I didn't notice a difference on my mossberg, but it already had a ported barrel on it. As far as patterning, I doubt the ports make a difference, but different brands and styles of chokes will pattern with different with different loads.

Velocity, shot size and choke length all play a part in it ( considering same size constriction).

Paul