the only time I really wish I had a mouse with the iPad is on written documents, but at the same time only ever use the iPad for light work in this area.
In my line of work [design] I barely ever have had the need for a mouse on the iPad, and use the iPad as a compliment device to my 'computer'.
Despite it being able to do a lot of tasks, it does some better than others, just like other form factors.
For sketching, manipulating images, reading and research, it is a great tool. For editing documents, no much so.
Use the right tool for the job or get a surface pro [which in my mind is more laptop than tablet....]