I've got a ported (Angle Ported by Ballistics Specialities), 12 Ga Beretta O&U, that I use for hunting and Sporting clays.
Muzzel jump is reduced, BUT not a hellava lot. I can't honestly say it is any quicker for me to get on the bird for the 2nd shot.
Felt Recoil MAY be reduced by 10% to 15%.
Patterns are probably 20% more even and have a "less dense" center core.
Increased noise level is there, but not so much that it is a problem. Worst case would be in a confined duck blind-- clays & open field shooting (pheasant etc.) it is not a consideration.
Is it worth the money?.............. not as far as I'm concerned.
Better to take the same dollars and have your gun (gun stock) PROPERLY fitted to your specific requirements.
Just some opinions from an 'ole geezer.