Marty I agree with you that the two roads you mentioned are overall more enjoyable than the Dragon for sweeps and scenery but I differ about the technical riding of the Parkway. I like the road but I find it very easy to ride bordering on boring from the technical or challenge perspective. I think the road is over engineered and the corners are to identical. They never seem to sharpen enough to apply the brakes if you are traveling the speed limit. In fact it is the one mountain road that you can set your cruise control at the legal speed limit and never touch the brake or throttle. Very nice leisurely cruise with excellent views of the mountains but not a challenging road to ride, unless your way over the speed limit. 
Foothills parkway is a favorite ride of mine. You are correct easy to set cruise at 45, the speed limit, put your feet on the hwy pegs and just cruise enjoying the secenery and never touch the brakes for the hole 19 miles. I usualy like to ride it at 55, ten over, makes it much more enjoyable.
Sad thing is many times there are folks on Harleys that strugle to maintain 40 mph on it.