I really don't see how in the world anyone can compare a Goldwing and an Ultra Classic??? These two bike are so wildly on the opposite in so many ways it's not even funny.
First off let's look at it from a purely Engineering point of view...
Harley's use very old engineering as a basis for their bikes. A few points are Swing arm ( double sided ), Engine, Structure of the frames( were as many Metric bikes use the engine as part of the structure.. harley does not) and Don't get me started on the springer...
Harley's run hot... and you can feel the heat when you're riding it.... Live with it will never go away.. sure you can get it down a bit..but there will always be more heat than a GW. On cool day there really isn't any heat issues.. but in the summer... OUCH!
I think everyone in here knows the true differences between a Harley and a Honda... regardless of the engineering and heat and ride.. most harley people are harley people and that's that.
I like Harley and I like Honda and Suzuki and Ducati and Kawi and just about anything that has two wheels or three in the case with trikes.
Bottom line is buy what makes you happy.. if it stops making you happy and you can afford it get something else.