I have a a laptop that I use instead of a desktop at work and then take home to do more work in the evening.. Although its screen isn't huge (15 inches diagonal), I find that perfectly easy to live with. The keyboard and the touchpad thingy, though, not so much. I keep a USB mouse and keyboard at work and never work without them. I also keep a set at home, but use these less often because I tend to work huddled up on a corner of the couch rather than at a desk. When I do use the one at home rather than try to get by with the notebook mini-keyboard, those are the days that my posts here are relatively typo-free.
Which reminds me, it's switching back and forth between radically different keyboard sizes and configurations that seriously hampers my typing skills. I now have a personal laptop that's got a bigger screen (18 inches diag) and a "full-size" keyboard, complete with number pad, so it's more like a desktop. On that, I get by just fine without plugging in a keyboard. Still hate the touchpad, though.