I have the full-size. We were issued an ipad (actually given one...company bought it, but gave it to us to keep), but given the choice between mini and full-size. The full size is a little better, I think.

Its hard to read in bright sunlight, and they do get hot and quit working. Keep that in mind if it's your sole-source for charts on board.

I don't see learning to read a sectional on an ipad as any different from learning to use a paper chart. It's the exact same data, read and used the same way. The only difference is that you can't lay a plotter over the chart and draw on it. For that reason, you may wish to carry at least one sectional for learning purposes, just to get a situational understanding of basic navigation, but the ipad and foreflight offers some significant advantages.

We use the cellular-capable ones and maintain 5 gigs of data to get weather, TFR's, and current information while plane-side, and it enables quick filing of a flight plan, from the cockpit. The ability to have VFR and IFR charts handy is very useful, even if you're just flying VFR. I think it's a good investment.