I think i would rather do the rearsets than highway bars, stock seats support you on your hips, highway bars put your weight on your tailbone, also when hitting bumps you are supposed to slightly raise your weight up and squeeze.
Better control, better form, also leaning into turns makes you use them abs, and corner carving is much easier when you have control. Stock pegs or rearsets IMHO. Of course I've had a goldwing with floor boards and that was nice to
my bikes; 80kz1000(project), 77 gl1000, 74 h2 (project)
Past; 78 kz1000, 83 kz550
Andrew