The Yaris is definitely not a performance car. If you want to burn some rubber, look elsewhere. Highway miles going 60 - 70 I got 42 mpg while running AC. City only I got mid 30's with AC and driving conservatively. Comfortable and handles well. Had a Tercel before that was still running well @ 177K miles. Tercel gave me no headaches ever, hope this car will be as reliable. Stereo system is so-so but does the job. Radio reception is poor. Interior is roomy, seats are nice, instruments are clearly visible. Everything is manual (windows, locks), so there's less stuff to brake. If you're looking for a reliable economy car that gets great gas mileage and doesn't brake the bank look no further.
If you're a do-it-yourself car mechanic, there's no better new car than the Yaris. Easy access to everything, air filter, oil filter, battery, transmission, brake reservoir/lines/valves, etc. No special tools required. This saves a lot of costly and annoying visits to the dealership.
I'd like to say more UMPF but it's an economy car, not a race car. Ground clearance on the low side.