We are up to about 20k miles in our Insight now and still getting 45-50mpg with no issues. My wife uses it as her daily driver and loves it. We will never sell this car - so much space, practicality, and fuel economy for the price.
Gas mileage, interior materials quality and space, reliability. Room in the back for a rear facing carseat, but as with most compact cars it sacrifices legroom for the front passenger.
I don't really like driving it due to the lack of cruise control but that's what we get for buying the LX. Handling can be scary above 75mph, especially if it's windy. I like to drive fast and it'll still do 45mpg at 80mph.