I'm not sure of Cg with the rail mount Andersen hitch, but the ball mount version shifts the load aft of the rear axle. To be honest, I didn't notice any issues when I was using the Andersen Ultimate to tow my 5er, and I have my B&W set as far aft as possible as well with no issues. I've heard others have had different results though, to include a workmate who swapped out his Andersen for a different hitch claiming stability issues, especially in wind. He didn't even get it home before turning around and going back to the dealer. His 5er was quite a bit to heavy for his 2500 RAM so it's hard to say what the real issue was. He seems happy with it now though.
Good luck. When you get everything dialed in these things tow pretty good, even in winds strong enough you start to get concerned about the rig ending up on it's side. Mine rocks quite a bit in some of the crosswinds so common on I-80 across Nevada, Utah, and Wyoming.