Impressive! Was really surprised at how little it taxed my system, usually I see my CPU graph shoot straight up. Would love to know how you optimized it as that's the biggest drawback with most HTML5 games I play.
Jekyll best serves a particular type of user and their needs. I'm a WordPress developer and make my living off it, but I absolutely hated using it for my personal site.
Now I can open my site in Textmate, make my changes, and use git to push to my server all in less time than it would take to do the same in WP. I don't give anything up(you can have archives, tags, and related posts in Jekyll) by switching and gain quite a bit of flexibility. Jekyll also fits into how I like to do things(ruby/textmate) which is incredibly important to some people.
So yes there are cases where Jekyll makes more sense. Depends on the user.