Are there any options available that utilize h264 as the screen delivery protocol in the browser? I’ve always just found VNC to be so finicky and laggy.

Cool demo!

We're working on taking a video stream from the frame buffer directly, ffmpeging it and streaming it down as video. We'll use VNC for input but not display.

Don't bother, it's not as performant as VNC (VNC overhead is higher but latency may be lower, depends whether you want to optimize for low latency and throughout versus server resource usage), especially once you take into account stuff like VirtualGL.