Has anyone used it?
Is it a security risk?
And how functional (slow) is it?

I used it 20 years ago to cruise the dark/deep web. There were some really spooky things going on there....

I ended up calling the FBI over some things I saw!

It's slower than conventional browsers.

Withheld, Thank you very much!

It's not a security risk unless you're browsing the "deep web" or "dark web", which isn't likely.
It's just a browser with some extra built in security, but it's usually used for places/people that have oppression in their Internet access.

I imagine if you're accessing soi/hyoerchat, that's not the case for you.

You can also get plugins and use proxy's and vpns if you're worried about surveillance for just taboit any browser/connection. Proxies and VPNs would slow you down, but the browser itself usually doesn't unless you've got a lot of things going on.

Keep in mind, the more security you have, the less things will work on some websites, because things are usually blocked for security. If you disable these protections, you will not really have any benefit from using a "secure" browser.