Like others said: Good overview, simple explanation of the security functionality. Nothing new though.
Basically it's the presentation of what you can find in the documentation. I would have preferred something else about the security
Fine keynote
Nice talk and explanation, but nothing new and nothing that you can find out in documentation.
Nice talk about the history and vision of Symfony
Impressive results that were presented.
However, too much about the problem, to little about the solution and it's pros and cons. Also, you're talking to developers here. Show us some code!