I haven't noticed anything that I would call bad flight characteristics. They fly nicely fast or slow. They need a good contrasting top/bottom color scheme to see them well, especially since you'll probably fly it out farther than most park flyers with the high top speed.

I'll fly mine fast for awhile (full throttle dives and low passes), then take it up high, kill the throttle, and glide it down. You definitely want dual rates. High rates give you plenty of control at low speeds, and low rates keep it comfortable at high speeds.