Checked the site, yea it must be new or never heard of it still.
It's actually been around for a long time, but I can't blame you for not knowing about it since it's one of the lesser known anti-viruses out there.
Also, Norton doesn't seem to max out my disk usage at all not running any scans, so it doesn't have too bad of a performance impact for me at least.
Webroot is a pretty neat option and light option, enough so that it can be used with other anti-virus software without conflicting too badly at least from my experience.