Advantages of the 16GB model:
It is$100 cheaper than the 32GB model.
It has enough storage to store most people productivity applications.
Advantages of the 32GB model:
It has a ton of storage, more than most people would ever need.
You can store almost all of your games and applications on it, 3-4 movies, and all of your music(or you could just use Apple Music or Spotify).
Really, it is based on how much storage you think you will need. There is no other additional advantage or disadvantage other than the price. So if you think you are going to need 32GB of storage, get the 32GB model. If you think you will use less than 12GB of storage(the amount left over after the OS) then get the 16GB version. If not, then get the 32GB model. It is all up to personal preference, though let it be known that the iPad doesn’t have expandable storage through a microSD card like some.