Yaris Questions

[Tokiko]

Hello all, I'm new to the forums, and have been trying to do as much research as possible on which car would be my ideal first car. I really like the gas mileage available on the yarises, and would love to get honest opinions from people before I nail down exactly which car would suit best.

I've been driving a '93 Cavalier since my grandparents moved to South Carolina back in the late '90's. I really do like this car, but it seems to be on its last legs.
From what I've seen and looked into, it seems Toyotas across the board do really awesome on gas mileage, and although I'm by no means a car expert, I kinda had my eyes set on either a Yaris or a Corolla.

Yesterday I took an impromptu drive to a local Toyota dealer just to get added info on both models, and the dealer made things quite difficult. Making it clear that I was going to be starting a new job in 2 weeks, I told the guy that I was just looking to get his opinion on which direction I should go, and instantaneously he said that -- not only would the Corolla be a better car, but that I "had to make my decision within a 12-hour window to take advantage of the deal he was able to strike directly with Toyota."

This was pretty disheartening because it really seemed like the dealer wasn't listening to me, whatsoever.

I have lots of questions I'd love to ask the members here...
So I guess I'll just start off asking these few:

Why did you pick a Yaris, specifically?
What would make the Corolla such a "better" car than the Yaris?
I understand the Hatch version is cheaper than the Sedan, but why else would the Yaris hatch be popular?

I've got a lot of questions in mind, still... but I figured this would be a good start and way of saying hello. ^^