IMHO I would spend the money and buy a B&W. You will NOT have the trouble hitching as mentioned above. I helped an inlaw hitch his Curt/RAM 25K twice and in all honesty it was a PITA compared to the B&W.
The B&W Patriot RVK 3285 $649 rail mount is a 18k hitch, compare it to Curt's 20K and you can see either B&W under rates their hitches or Curt over rates theirs.
BTW all Curt 5er hitches are Made in China and all B&W products are designed and Made in USA with US components.