My 7 inch tablet is as hard to see in the sun as my smartphone. Both use batteries pretty fast when the screen is turned on, even faster when the screen is set at full brightness.

Some tablets have a GPS chip in them, mine does not. If mine did, I could see having it as a backup GPS with map. Specifically, MapWithMe android mapping app allows you to load road maps where you have a wifi connection, can use them later off line. The Lite version is free. But that works best if you have a clue where you are, thus the GPS chip adds practicality That said, I would leave it turned off until I needed it to save power.

I bought my tablet to take on a tour, did not want to take my netbook. It was great as a wifi device for checking the news and weather, for reading files, occasional e-mailing, etc. I bought the smartphone later, on my last tour only the smartphone went along, the tablet and netbook both stayed home.