I have the B&W gooseneck setup and the companion. I have two gooseneck trailers that I pull and use the companion with my fifth wheel. The gooseneck horse trailer and fifthwheel pull like a dream and I do not know it is back there. The flatbed gooseneck lets me know whenever I go over any bump. Most of what you feel is due to the percentage of weight on the hitch. Since you can't (very easily) move the axles, you might want to consider shifting more weight to the front of the trailer. I do not think simply going from gooseneck to fifth wheel hitch will not fix your problem.
