I bought a Prius 4 yrs ago and I like the car. With the fact that Honda is discontinuing the car, and I didn't want Toyota to earn all my money so I decided to buy a new Insight. Surprisingly my decision is well made. Like I said Prius is a good car, I can get 60 MPG if I drive it really carefully (by pissing off many other drivers). But Insight makes you forget that you are driving a hybrid and still get you pretty decent mileage. Honda is definitely more fun to drive compared to Toyota; the handling is much better. Although its not as spacious as to Prius, its not bad at all. Bottom line, both cars are good, but Insight is a car with more fun.
Driving and handling
Make the AC to run consistently no matter what. Stop the engine when the gear is in N. Currently, you have to step on the break but many people like me who doesn't like to step on the break while waiting.