Others may have different experiences but I never have noticed a difference in the recoil of ported and non-ported barrels. Porting may keep the muzzle from jumping as much and ported barrels are louder but other than that, I see no advantage.
As far as the porting on Mossberg barrels, the ports on my 930 are well done, no sharp edges on the interior, etc. My other Mossbergs are non-ported.
The Limbsaver slip on pads are excellent products. I use them on several guns.
I hope that helps some.
Thanks,
Clark