I full time and I run a Verizon MiFi and a Wilson Sleek and it works great. I do have a laptop, which takes up much less room and is portable. Lets me use it at the kitchen table or sit outside, etc. Can even take it (and the MiFi) to a park if that's what you want to do.
I personally would not go the phone route, but I do know some folks do. Not all phones can be turned into a hotspot - It depends on your carrier. A MiFi allows you to run several devices at once (computer, printer, ereader, etc) and generally you can find a data plan for a not too terrible cost. I also seem to have read that you can't talk on your phone at the same time you're using it as a router. Someone please correct me if that is an incorrect statement. Also, because the phone has it's on data plan, you may be able to get by with a smaller data plan for your MiFi.
I have found, as a full timer, that dedicated systems work better for me then 'one size fits all' systems.
Tim