We've had several round-a-bouts in my area for probably 12 years or more. I find that people that hit them aggressively are my friends, it's predictable what they will do. People that are tentative and afraid to enter them make traveling through one very unpredictable and unsafe.

Of the two traffic circles here I travel regularly by car, the big diameter one works better. This is also the one that I bike through sometimes. It's fine if I'm not in rush hour traffic.