The focus of my design work has shifted over the past years. The most important objective of my client's presentations is to make a good impression as an attachment to a "cold email". What is a good summary presentation that you can send ahead of a (possible follow up) meeting?
It is not a dense "Executive Summary", one page of dense text (10 point font or less), full of buzz words and jargon. In fact, it might not be a summary at all. Investors say a huge number of deals each day, and don't want to have to sit through a full presentation to understand what it is you are actually doing. The main purpose of that live presentation is to get an impression about you, the CEO, not to understand the business better. So in 2017, your presentation needs to be able to stand on itself, convey the story without you being there to explain it. A teaser deck that creates interest is good, but it should not be so mysterious that the investor does not have an idea what you are doing.
Having said that, just attaching your full deck and hit "send" does not work either. I usually suggest to take certain bits out. These are usually the "admin bits" of the presentation, detailed financials, company milestones, go-to-market strategies. This is the more dry content that can be discussed after the investor has bought into the big idea. Also, some of this information might be confidential and not suited to be emailed out to investors you do not know very well (yet). So, the summary presentation is actually the full presentation with certain sections left out.
This requirement to be able to be self explanatory has changed my design style somewhat: longer headlines, and yes more text. The core deck is optimised for a speed reading audience, rather than one that sits down and listens.