This is a mostly read only web page. Half a second to load? You're barely going to lose anyone, if you lose anyone at all. Hacker News routinely runs me ~300ms to load and has zero personalization, Facebook takes over a second and a half before anything displays, as does Youtube (on a refresh, no less, so things should reside in cache locally!). Hitting a random person's LinkedIn page (once I've passed the verification, which is a whole different issues) takes 1.2 seconds. Etc.
Now, admittedly those are including the latency on my end, but the point is, no one is so meth addled that a page loading after half a second (or even a full second!) is going to have much effect on engagement. Even the studies that have been done (that I have some major issues with) only really start measuring anything significant well after a second or two.