It's not the drop bars that cause a bike to feel twitchy. It's the design of the frame, and to some extent, your setup on the bike. What feels like twitchiness to someone new may be a desirable characteristic to someone else. After all, you want to be able to quickly dodge things, or to maneuver quickly in traffic or wherever. Some of those bikes also get very stable at higher speeds. But I wouldn't worry about the drop bars. It's not what will make any bike twitchy. A touring road bike is generally less twitchy than a road racing bike.