Thanks for the feedback, Rob. I'm sorry you were disappointed.
I agree that many people do understand things like "right size images": This has been preached by Steve Souders for years so some really should understand that. However, the data shows that many developers either do not know, or do not necessarily understand the impact -- particularly in a mobile-first world where this becomes even more important. I expected for some experts to get little out of the advice itself, and more out of the importance of that advice -- seeing the impact of these decisions on memory and CPU / GPU utilization. For instance, even looking at my own blog as well as yours, there are a lot of anti-patterns for performance that I have opted to ignore (again, as I'm sure you have) : tons of script throughout the page head / body, multiple registrations for document ready, antiquated if IE checks, etc. But knowing the impact makes us all more inclined to make changes.
Your point is very valid, though, and I'll perhaps aim a little higher next year should I agree to do another session. What would you prefer to see instead? What would be useful to you, at an expert level? Thanks again for the feedback. Very useful.