Log examine page load & render time in the console

Because you are what you measure.

I'm seeing load & render times of ~2500ms when I run cycledash locally. It's no different when I undo the parallel XHR change. This means that parsing the VCFs and rendering the page is the bottleneck, it's not network activity.
This doesn't seem like something that should be living in ExaminePage.js—maybe in something like `instrumenting.js`?