We got about 30% off MSRP on our GD Reflection fifth wheel - but it was in Georgia. We pulled it for 18 months with the rail-mount version of the Andersen Ultimate and loved the combo (with the addition of a Demco Glide Ride dampened pin box to lessen the effects of our wonderful highways...). We were recently forced to get a different hitch to fit the Ford factory puck system on short notice. I DID NOT want to give up the Andersen. With a Momentum, use the CAT scales and be careful of the load limits on the truck's rear tires. With the short bed, you may also have to turn the Andersen hitch and pin adapter around to reduce swing radius of the pin box for the side rails and tailgate.
Rob
PS: the Grand Design Owners Forum is a great place to discuss GD RVs with a lot of great folks, too.
