I have taken several fairly long trips with a good friend who rides an 07 ultra something or other. Although I am not a racer wannabe, I do enjoy some spirited riding in the twisties. I can assure you that someone with the intention of riding his or her Harley at a spirited pace through a twisty section will not be embarrassed by its performance. I snow ski with this guy from time to time as well and it is the same when it comes to getting down a ski slope. Skill and risk acceptance will mostly determine the speed at which one skis.
My opinion is that given two people with roughly the same abilities and amount of comfort with risk can ride a twisty section of road at about the same speed whether on the Harley or the CB750. Each bike will excel in different areas of the curve, and may use different braking and accelerating techniques, but in the end, can wind up at the destination at about the same time.
I have ridden his bike a fair amount and have actually been fairly impressed with the cornering ability, even though I am not in my comfort zone with the w a y it corners.
I say that if you got a good bike well below blue book value, then WAY TO GO! The Harley will hold its value fairly well, so you should always be able to get a good return on your money down the road!
Additionally, when you stop for a fill up, a meal, a drink or to shoot the breeze, it doesn't matter what you are riding. It matters that you had a good time on your bike and had a good time with your friends. Maybe enjoyed some scenery, faced a storm or a careless driver and lived to tell about it; took some curves too fast and some too slow, broke some speed limits and got lost. The guys you don't want to spend time with are those on either side that can't relax and have a good time because what someone else is riding.
Peace.
Kirk P.