I came from a much smaller set of phones (iPhone 1, iPhone 3GS, Droid Incredible)... so I was also really skeptical.

For me, it's probably damn near perfect in terms of form factor. It took a day or two to get used to holding it, but after that it's been nothing but awesome. The extra real-estate is really appreciated. I'm a bit faster at thumb typing because the spacing is a bit more comfortable.

I dig it.