Hi,
When I Google'd for this issue it was interesting that the first hit was to this thread, and it's exactly the same use case as for me.
I work in the IT industry, and I go to lots of industry specific meet ups. The are a huge number of people (like me) taking photos of the slides (and I'm sure a large proportion of those use Evernote). Right now the best bet is to sit as close to the front as possible, because cropping the slides afterwards is too time consuming.
With my new iPhone 7 plus there's another reason why I'd prefer not to crop the slides - you now get 2x optical