I've had my Yaris for nearly 4 years now and sadly I just sold it as I didn't need it any longer. But I can attest to great fuel economy, fantastic quality, and a terrific resale. I have 125000 klm's on this baby and never once in the dealer for ANY problems whatsoever. Regular oil changes 8-10000 k's etc., and never a moments problem. So much so, I now have a 2011 Corolla.
Fuel economy, reliability, cost-per-mile inexpensive, easy handling and just plain fun!
Better O.E. tires. Mine wore out at 53000 K's. Not good. And perhaps a slightly peppier engine but not much.