The '04 Road King that I have had somewhat iffy brakes to start with, or so it seemed. I tried a couple of simple fixes, one that really seemed to help: lash the brake lever to the grip overnight as tight as you can get it...and the response of the front brakes got much better. I will be pulling the calipers this week to clean the pistons and inspect the pads. I will put better pads next time...don't like the factory versions. In addition, I think better tires will make a huge difference. The stock dunrocks don't really grip for crap....turning or braking.
Further, I came off of a sportbike and was very surprised at how well the big girl can dance. Sure, she'll never be a rockette, but she can really shine in the twisties if you insist and aren't afraid to sharpen the floorboards.
All that said, even Road Kings aren't for everyone. Do a test ride. Find what you like. Then ride the crap out of it.
Because it is my bike and I like it that way!