Just got my SBEII back from Rob Roberts/Gobbler Guns.....there is a somewhat detailed summary currently on the boards. As far as porting....Rob was very forthright and even has it on his website...this procedure NEITHER....Helps or Hurts Pattern Performance....it merely reduces muzzle jump allowing greater control for a follow up shot. I also understand it makes the weapon somewhat louder. I had mine done, as I hope to use it some on Waterfowl as well. Nutshell.......his work is flawless/fast/ and customer service is top notch.
PS: They use a high tech lazer type device to create the ports as opposed to drilling....the results are extremely uniform and precise. Hope this helps.