To be honest, I prefer the original java version over the html5 version. It uses less resources, and doesn't cause my browser to crawl while it's running. The java version starts chugging on my laptop at about 20 transistors, this chugs with a third that many. Also, the java version had a zip file you could download to use it without being connected to the internet, which this one doesn't.
I'm unsure of why you got down-voted. Your experience is your own, and of course you're entitled to your own opinion.
With that said, I haven't seen the poor performance you described. Have
you tried another browser? Or a newer version (if any) of your browser?
Have you tried it with a separate browser instance without tons of tabs
open? If you continue to have issues, report the performance problem on
the Github repo and include full browser version and system info.
