Yeah I have big fingers so I'm hoping with the Droid X it will be easy to compose emails and text messages quickly, without having to slide out a keyboard. I can type like 40wpm on the hardware keyboard, but I end up leaving it slid out on my desk during a long back and forth conversation.
I doubt I would use the big screen for movies and such because I have my iPad for that sort of thing and I'm sure the battery life would be atrocious for movies with that huge screen (although technically the CPU is 45nm as opposed to 65nm on the Evo 4G so it theoretically get better battery life).
My only issue is the phone is obviously not rooted yet, so I will lose my WiFi tether capabilities for my iPad until either 2.2 comes on the phone (some rumors say it is built in, some say an update soon after release) or they root it. Root will take awhile though because of the additional NinjaBlur interface and the fact that it will probably be immediately backordered so the developers will take awhile to get their hands on it like with the DI.
But in reality if I need to surf the web for something, I will have a 4.3 inch screen to do so, which is more than adequate. Anything else like updating apps and whatnot can wait until I get to a WiFi spot or home.