Pros / Cons on Button vs Bookmark

Hi all,

I am fairly new to the PBI world, and was wondering what is your view on Pros and Cons for using Buttons vs Bookmarks for those of you who are working with more complex datasets, where a lot of Bookmarks or Buttons would be required. 

Building a new dataset and would appreciate a bit of context on both. Which you think are better when your report will have 200+ pages.

1. When you use many visuals on a single page, is it worth trying to figure out in which Bookmark you hid some shape or worth to create separate pages?
2. When a visual take some time to load, is it reasonable to duplicate those over separate pages and use Page Navigation/Button action or is it right to use bookmarks? So you don’t have to load time-consuming visuals again when switching between report pages?
3. Is it worth fiddle to update Bookmark each time you make a change to your report layout or good to have separate pages/buttons?
4. Use Bookmarks grouping or several pages, which one is easier when you have far too many actions to do
5. Hiding visual does not run a query, which helps performance. So should I just use Bookmarks?

Any advice would be greatly appreciated!