Build separate pages or not
<p>I have about 20 grid views that I have to create. All of them are pretty standard across the board. Just take IEnumerable T and display it in a grid view, that's it. </p>

<p>I would prefer to create one aspx page and have the grid view be dynamically generated by using ITemplate. And I guess for the data source use IEnumerable Object. </p>

<p>Are there significant performance considerations between doing it the way I'd like to do it or would it be better to go ahead and build the 20 or more grid views on separate aspx pages?  </p>

<p>An example of a concern I have is taking List T and casting to IEnumerable T where T is type Object. </p>
