Pros:
- Can hold loads of documents, approach plates, charts, various other information.
- May be useful to show Skydemon or other applications when beneficial in the lesson
Cons:
- You may still need a backup chart, set of approach plates etc. to cover tech issue or battery problem.
- Cockpits get hot, tablets shut down when overheated.
- May be a major distraction as well.
- Must be used in such a way that it does not impair view or obstruct controls or otherwise becomes a hazard.
I don't have one/don't use one myself but this is based on what I have seen, experienced with students and read about tablets in cockpits. I don't really have a preference myself to be honest but stick to a mix of a paper chart, some charts/plates and a kneeboard, and some apps on my phone that assist with flight preparation and such.