Drawing directly on the screen is a ton lot better than being portable. I mean, what's the point of being portable if you're going to hook it up to your completely not portable computer? And if you're gonna take your laptop and tablet and draw on the go, I don't know what to say...
Anyways, a decent pen would be a good investment, but I am not good enough with a tablet. I can't put the tablet directly on the keyboard of my laptop, so this distancing thing is difficult. The digital editing ability gain is lost to the direct interaction of the pen and paper. Able to fix the screwups that shall happen more often cause the tablet ain't all that and a bag of potatoe chips.
Livescribe smartpen has a camera inside. It takes pictures of students' notes as they write them down. Besides, a built-in microphone saves time because it has a recording feature of the speaker giving a lecture. Livescribe Desktop software allows to transfer all notes and essays to the PC storage.