A lot of folk tend to compair the wrong cars from manufacturers against each other. The Stilo is really a Focus competitor and priced/sized accordingly, the Fiesta is more of a Punto competitor.
However when Fiat still made the 1.2 Stilo it was slap bang in the middle of the Fiesta market price wise, and you got a whole lot more car for your pennies.
When i picked my Stilo it was a toss up between the Fiat and a new Fiesta. Both priced within a few hundred quid of each other, the Fiesta had aircon, metallic paint and alloys, the Stilo had metallic paint and a funky trip computer and was a much bigger car. I think i picked well, but in 3 years time both cars will be worth the same, but i bet the Fiesta is more reliable being less technical.
That all said in done, i'm glad i picked the Stilo, its the right sized car for me, it's cheap to keep, and there seems by and large to be a good scene for the car.