Do you use an iPad for "productivity"?

I'm debating between a laptop (macbook air or pro) versus an iPad. I have a desktop at home, and access to desktops at school, so I might be able to get away with an iPad being my "mobile" computer.

If you use an iPad for any sort of productive work, can you provide any insights and opinions on it? For example, do you use an external bluetooth keyboard? Maybe one of those built-in covers/keyboards? What apps do you use?

Thanks Apple Core!