I recently switched from a Pearl to a Curve.... mainly for the full QWERTY keyboard (SureType is pretty great, but nothing beats QWERTY).
Anyway, the screen is larger, yes. In terms of being "better," I think that's subjective. It does have a higher resolution because it's wider, but it's the same number of pixels per unit of measure (so it's basically like they just added additional pixels onto the screen to make it wider). The display is just as vivid and bright, and it displays the same number of colors.
I've found that I like it a little better, especially in the message application (you can see more of the subject line since there's more room to display it), and browsing is slightly nicer.
Anyway, if you want more room on your screen, the Curve will certainly provide it. And at first, the QWERTY will be a little awkward - the buttons are smaller (there's a lot more of them) than the Pearl, so you have to learn to be a little more careful when typing, but I got used to that very quickly (for a while, I was mashing 2-3 keys at the same time!
)... but you'll love QWERTY (no more selecting which word you REALLY mean!).
Hope this helps!