It was interesting.....I probably wasn't quite the target audience for this as I've use xhprof very briefly before. I think the talk might (or might not, who am I to judge) be improved by:
* Explaining what the call graph diagrams mean a bit more clearly. The fact that the text on the diagram isn't easy to read probably isn't overcome-able, but explaining what the hierarchy of calls represents in general could be hammered home a bit more. And then for each of the scenarios tested, needs to be said more explicitly, as although that is clear when it's on a computer screen, it's not so clear when viewed through a projector.
* The 'hook' of the talk showing that naive measuring of optimizations might not be worth the time spent on it....instead of spending the time on that, it might be worth spending time on a more complex scenario (maybe something involving Doctrine) where there can be a considerable amount of time spent on code that isn't very visible to the programmer.
btw the description of the talk might be better focused - I enjoyed hearing about hearing about xhprof....but if people read the abstract and were expecting a "few options" rather than a nice focus on a particular tool, they might feel their expectations hadn't been met.
A nice little introduction to Go.
Need to practice speaking very slightly more slowly. Wasn't ridiculously fast, but was quite a pace.
Maybe need to break talk up into sections slightly more, with a clearer break between the sections, as the parts seemed to roll into each other.
Code on slides needs to be waaaay clearer. I could read it, but only because I was directly in front and quite close to the screen.
More time could have been spent on introducing channels as it's probably the most important bit of the talk. A clear "why" channels exist to begin with, then a really trivial example e.g. using the same function twice, rather than inline definition of a function, and then finally a useful example of why you would actually want to use channels.