I owned my ECHO for five years and if it wasn't for the need of more space for the child seat, I would still have it. It is a lot of fun to drive, sprinty and light. The inside is roomy albeit cheapy (you have space for everything you want). The gas milage is unbeatable (I averaged 35 MPG on my daily usage, meaning about 20-25 bucks a month on the gas). The handling was always challenging, though, especially with strong winds on heavy rainfall (not rare in Seattle). Once, only my rally driving training helped me keep the car on the road when I had to make an abrupt emergency maneuver on a wet road to dodge a deer. Also, with more than once passenger, the engine is a little underpowered.
Gas milage, power/weight ratio, visibility
Less cheapy interior. ABS. Stability. Accessibility of the rear seat.