I can chip in some opinion regarding what you're looking for. I don't really use the iPad as a productivity device. More of an information consuming device. Its a great reading device before bed time or when I'm lazying on the couch. What I need is a device that turns on and off instantly like any other consumer electronics and doesn't require constant charging. So the iPad is perfect for some light reading, surfing and some games along the way. I also have my music library and pictures loaded too. But its more of a secondary feature for me. Say when I need it, I'll just play it. It just complements the entire experience.

What I like the iPad the most is during bed time. I use to do the same things on my mobile phone but its battery life isn't so good (using Android phone ) and the screen is smallish. I have always wanted something more longer lasting like a book. The iPad has been perfect. I'm no Apple fan, I could have been ok with any tablets but the iPad is kinda like first to market so I just get it.

I think you can use the iPad for work and studies to a certain extend. In my opinion, its good for knowledge reference. There are many apps like periodic tables and referencing apps. Its great if you want to do a quick reference on the iPad. IF you can load your entire textbook into the iPad, its better! But don't expect that to happen anytime soon (due to licensing issues, etc). You can also do office apps on the iPad if you got the keyboard dock as well.

Unfortunately if you plan to use the iPad for something more serious, you may stretching it a little too far. In which case, you can admit it that you want it for fun I'm just sayin'

I think thats a smart combination. If you are using a recent smartphone, you could even use Mobile Hotspot feature. Its not fast but it gets the job done. But the MiFi idea is cool. Cheers!